Text in red represent my additions.
1. In the beginning was the Word, and the Word was with God, and the Word was God.
in the beginning; i.e.., at the dawn of creation, when time began, when all created things began to be, the Word was already in existence,-from which it follows that the Word had no beginning, and consequently was eternal.
Was. The imperfect tense (Greek: en) is here used to signify continuous existence; had the perfect tense been used a cessation of existence, following upon the beginning of created things, would be implied.
The Word, means here the Second Person of the Blessed Trinity, as is evident from verse 14, where it is said, “The Word was made flesh.” it is only St John who makes use of the term Logos, Word, to signify a person; and this he does not only in his Gospel, but in his First Epistle (1:1) and in the Apocalypse (19:13). In other parts of the Old and New Testament the term, logos, usually means speech, word.
It is a grave mistake, however, to hold as some do, that St John got his idea of the Word or the term Logos other than from biblical or divine sources. First of all the name Logos is not uncommon to the language of the Old Testament. The sacred writers often speak of a divine envoy, Maleach, who was to be the final Mediator (cf. Gen 16:7, 13; Ex 23:20; Hosea 12:4, 5; Zech 12:10). They personify divine Wisdom, with which Memra, or Word of the Eternal, is eminently endowed, and make both divine Wisdom and the Word special agents of divine activity in the work of creation and in the world (Prov 8; Ps 106:20; 109:1; Isa 55:11).
It was natural, therefore, that St John, in characterizing the Messianic action of Jesus, should identify the Christ with the Angel of the Covenant, the Wisdom and the Word of Yahweh, since these are the personal and external manifestation of God. Perhaps also St John was moved by the divine inspiration to make use of the term in speaking of the Second Divine Person, in order to refute many of the heretics of His time who had abused the term in expressing their own errors
The Word was with God; i.e., this Second Divine Person existed from eternity with God the Father, one with the Father in nature, but distinct from Him in person.
The Word was God. This clause expressed the essence or the nature of the Word. The use of the article “the” before “Logos” shows that “Logos”, and not “Theos” (God), is the subject of the clause. The identity, therefore, of the nature of the Word with the nature or essence of the Godhead is here distinctly declared. It is absurd for the Arians to say that the use of “Theos” here without the article means a being with a nature inferior to the Supreme Being.
2. The same was in the beginning with God. This verse is but a recapitulation of the first verse.
3. All things were made through him. The Evangelist now passes on to a consideration of the relations of the Word towards created things; and he shows that all things that have had a beginning have come into being by or through the Logos. The Arians maintained that since creation was through the Word, the Son was therefore inferior to the Father, forgetful of the fact that, as the essence and nature of the Father and the Son are one, the action of the one must be the action of the other. The Father and the Son are inseparable in the creative act, precisely because they are one in nature.
Was made nothing that was made. While this is the usual punctuation (i.e., “All things were made by Him: and without Him was made nothing that made.) of these words, there is equal authority in both Latin and Greek for putting the period after nothing, and writing the remaining words with the following verse thus: “What was made in him was life,” meaning that living creatures were made to live by His power. In Him means by Him; and life is taken passively, meaning made to live, vivified. Cf. Summa Theol. ia, qu. 18, a. 4.
4. In Him was life; i.e., in Him, as in its cause, was that supernatural life which, through His revelation and grace, He has communicated to men. The life, then, here spoken of was supernatural, of which men and angels only are capable.
And the life was the light of men; i.e., this Divine Word who was the source of all supernatural spiritual life was also the source and author of the faith which men have. “The light of men” means, therefore, their faith; and the Word, who is the source and author of faith, is the cause of the faith which men possess.
5. And the light shines. The term “light” here means the Word, and this Divine Word or light has been shining on men from the beginning, enlightening them through their reason and through divine revelation. he has offered the light to men, but men have been free to accept or reject it.
The darkness signifies the moral obscurity to which unbelief had reduced man,. Sins are “works of darkness” (Eph 5:11; 6:12).
The darkness did not comprehend it. The meaning is that the majority of men did not believe in God whose existence and attributes were manifested by the visible things of the world from the beginning; nor did they believe the revelation which God gave them through Christ. This rejection of belief in God and His revelation was possible only because men were free agents.
6-8 There was a man sent from God, ect. The Evangelist now introduces John the Baptist and his mission for two reasons: (a) as a witness to prove that our Lord was the Messiah; (b) to show that the Baptist himself was not the Christ, as some erroneously thought. John’s mission was a divine one, it was from God, but it was only to prepare the way for the Messiah and to give testimony to him.
9 That was the true light, which enlightens every man that comes (was coming) into the world. The most probable Greek construction of this verse is that which connects coming with man, which gives the meaning that the Word was the essential, everlasting light which enlightens, so far as he is concerned, every man born of woman. If this true light does not enlighten everyone, it is because men are free to prevent it, just as they are free to conceal themselves from the light of the sun shining in the heavens. The Word, therefore, not only at His coming into the world, at His incarnation, but from the very beginning, was the cause and source of the faith of men; but men, of course, as free agents, were and are able to reject belief in God and in God’s revelation
Note: The above translation: “that was the true light, which enlightens every man that comes into the world,” and the interpretation following it, while common in the history of translation and interpretation is not the translation/interpretation commonly accepted today. Most modern translations indicate that it is the light which is coming into the world: “The true light, which enlightens everyone, was coming into the world” (NAB). For many older translators/commentators this made no sense because of the beginning of the next verse: “He was in the World.” If He was in the World, how could He be coming into it?
Because His coming was based upon the promises of God, and because God’s promises are assured to happen (for God is faithful) , the Messiah was known as “the Coming One;” the One whose coming was certain. The meaning of verses 9-11 seems to be: “He was coming into the world, that we knew for certain; yet when He was in the world, the world knew Him not. When He came to His own people, His own people knew Him not.”
10 He was in the world. “He,” i.e., the Word was in the World from the time of its creation, conserving it in existence, “sustaining all things by the word of His power” (heb 1:3). The Word was God, and God is everywhere by His essence, by His presence and by His power. Thus nearly all the Fathers understand the reference here to be the presence of the Word in the world, as God and Creator, before the Incarnation, from the very creation of the world. Maldonatus, however, holds that there is reference here only to the presence of the Word in the world during His mortal life.
Note: I understand the meaning of the verse as follows: He was in (i.e., came into) the world by being made flesh. This is the world which He Himself had made, yet this world He made and came into as man did not know Him.
And the world was made by Him, ect. Although the Word was the Creator and Conserver of the world from the beginning, still the majority of mankind had failed to recognize Him, transferring the worship due Him to senseless idols (Rom 1:23).
11 He came unto His own, ect. All the Fathers understand this to refer to the Incarnation of the Word. By His Incarnation the Word came into His own world which He had created and conserved; and in particular He came to His own chosen people, the Jews, and they “received Him not,” they would not believe in Him, but on the contrary rejected him.
12 To all who did believe in Him, (Whether Jew or Gentile, the Eternal Word) gave the power (i.e., the grace) to become (the adopted) children of God. The faith of those who did believe in Him was the effect of grace and a necessary condition of the justification which followed and which made them children of God. Faith, as the Council of Trent teaches (Sess 6. can. 6, 8) is the root of justification, it is the condition sine qua non; but faith is neither the formal, nor even the meritorious cause of justification; men are justified by charity which follows upon faith (i.e., by “faith working through love,”)
Note: for the important relationship between faith and love in John, see the Jerome Biblical Commentary’s article “Johannine Theology 80:25-26, 35-38. See also the commentary of 1 John 4:7-5:12.
13 Who are born, not of blood…but of God. This shows that while men and the will of men, are the cause of carnal generation, it is only God who can be the cause of spiritual generation through faith and Baptism. This was the argument against the Jews who considered themselves just because they had Abraham as their father.
14 And the Word was made flesh. Some think this clause should be introduced by for instead of and, in which case the Evangelist would be assigning the cause, or the reason, why those who received the Word were made sons of God. “Flesh” may be only a Hebraism for man, or it may have been used intentionally against the Docetae-heretics who denied that Christ had taken flesh because they considered flesh to be essentially corrupt.
Dwelt; i.e., took up a transitory abode on earth among me,- literally, “pitched His tent or tabernacle.” The Incarnation of the Word was permanent, ut His visible dwelling among men was not so.
And we saw His glory. St John is here proclaiming himself to have been an eye-witness of the glory of the Word.
Glory as it were, ect.; i.e., such glory as was befitting and possible only to the Only-begotten Son of the Father.
Full of grace and truth. These words are to be joined with the first part of the verse, so as to read as follows: “And the Word was made flesh and dwelt among us, full of grace and truth.” The clause, “and we saw His glory,” etc., is parenthetic. Our Lord was “full of grace” in the strictest and widest sense of the term, both as God and as man, and hence He was an overflowing source of sanctification to all men. He was “full of truth” as containing all the treasures of wisdom and knowledge (Col 2:3), and as being the all-wise and infallible Teacher of faith and the way to Heaven.
This was He, ect. The Evangelist more probably is here giving by anticipation what he descries more fully in verses 29-30. He is citing the testimony of John the Baptist relative to the Incarnation of the Word “full of grace and truth.”
He that shall come after me, ect.; i.e., he that shall succeed me in the exercise of His public ministry “is preferred before me” in dignity, “because He existed before me.” Our Lord being eternal existed before John the Baptist, and was superior to the Baptist in dignity, and preferred before him in the designs and counsels of the Eternal Father.
And of His fullness we have all received. These are the words of the Evangelist continuing what was said in verse 14.
Grace for grace. This is explanatory of the preceding clause, and means, according to the more probable opinion of Patrizi and others, the more abundant and perfect grace of the New Law, as compared with that of the Old Law. The opinion also seems very probable which says that the above phrase means a succession of graces, one after another.
17 For the law was given by Moses; grace and truth came by Jesus Christ. The Evangelist had already asserted the superiority of our Lord over John the Baptist, and now he proclaims Him superior to Moses, Through Moses the Jews had received the Law which pointed out man’s duties, but did not of itself give grace to fulfill those duties; whereas Christ, the author and source of grace and truth, in the New Law has given to the world not only a thorough knowledge of the things necessary for man’s salvation, but abundant grace also to perform all these things.
18 No man has seen God at any time; i.e., no man while here on earth, at least while living the life of the senses, has ever seen God as he is in Himself. When we read in Scripture that Jacob or Job or Moses or Isaiah saw God, the meaning is that they saw Him represented under some visible human form, or as an angel who had assumed human appearances in order to represent in some degree the glory of God. St Thomas, however, holds that Moses and St Paul here below enjoyed while in rapture a real vision of the divine essence.
The angels and saints in Heaven see God as He is, they behold His essence, but even then only according to their own capacity and not comprehensively. As God is infinite in essence it is impossible that any creature should see and understand Him perfectly and completely. The present verse seems to assign the reason why the New Law and the gifts of Christ are so superior to the Law of Moses; namely, because Christ who is consubstantial with the Father and knows all the secrets of the Godhead, has declared the doctrines and mysteries contained in the New Law.