What follows is my translation of St Thomas Aquinas’ comments on 1 Cor 1:1-3, excerpted from his First Lecture on that Epistle, 1:1-9. The reader should not in any way, shape, or form, consider it authoritative. Text in red are my additions. A fine translation is available online.
St Paul divides his letter into two major sections: the greeting (1:1-3) and the message, which begins in verse 4. Concerning the greeting there are three things to note: (a) he begins by naming the senders of the letter, namely, himself and Sosthenes; (b) then the addressees; (c) and finally he wishes them grace and peace.
Concerning point “a” he mentions himself first as the primary sender, identifying himself with the name Paul. We have already dealt with the meaning of this name in our lecture on Romans, and so we will merely mention that the name is a sign of his humility; for Paul designates a small amount, or indicates humility: Though you are little in your own eyes, are you not the head of the tribes of Israel?” (1 Sam 15:17); “Thou hast hidden these things from the wise and understanding but revealed them to babes” (Matt 11:25). Note: Paulus is a Latin moniker, the word is derived from “parvulus,” the word used for “little” and “babes” in the Latin versions of the texts just quoted.
After naming himself he goes on to identify his status. As befitting his humility he does not first mention his status as such, but rather how it was obtained, namely by the fact that he was “called,” for one who serves God does not take the dignity to himself “but is called by God, as Aaron was” (Heb 5:4). Only after this does he mention his dignity as “an apostle of Jesus Christ.” Without a doubt this is the highest honor in the Church. The term itself means “one who is sent,” for they were sent by God as ambassadors in His name: “He chose from them twelve, whom he named apostles” (Luke 6:13), and in Ephesians 4:11 God has appointed in the church , first, apostles.” Finally, he closes out the description of his dignity by once again referring to its origin: “by the will of God.” This refers to the will of God’s good pleasure; the act of his salvific bounty whereby he chooses those who hold office in the Church: “The government of the earth is in the hands of the Lord, and over it he will raise up the right man for the time” (Sir 10:4).
However, on occasion God establishes some in authority on account of the sins of His people: “He makes a man that is a hypocrite to reign for the sins of the people” (Job 34:30), these are men not established according to God’s salvific will but rather according to his indignation: “I have given you kings in my anger, and I have taken them away in my wrath” (hosea 13:10).
In the second part of the greeting (“b” above) St Paul mentions “Sosthenes, our brother,” possibly because he is the one who had delivered to the apostle the information about the problems then taking place among the Corinthians. He refers to him as “our brother” to show that it was not out of hatred but familial charity which led him to give the report: “Reprove a wise man and he will love you” (Prov 9:8).
Having finished identifying himself and Sosthenes as the senders of the letter, St Paul turns his attention to the addressees, focusing first on the principle recipients whom he identifies in three ways. (The Saint means by “principle recipients” the Christians in the city proper, rather than to those outside its immediate boundaries. See next paragraph). He identifies them first by their environment: “the church of God which is at Corinth,” meaning Christ’s faithful assembled at Corinth: “I will thank thee in the great congregation (Ps 35:18). The Greek word for Church, ekklesia, means a community “called out,” i.e., a congregation. In the Greek OT the word was often used in the context of the people gathered for worship, as in the Psalm the Saint references. He then identifies them by the grace they have been given: “To those sanctified in Christ Jesus,” meaning those sanctified in the faith, the suffering, and the sacraments of Jesus Christ: “You were washed, you were sanctified….” (1 Cor 6:11); “Jesus also suffered outside the gate in order to sanctify the people” (Heb 13:12). Lastly, he identifies them in relation to the source of grace: “called to be saints,” for they came to be holy in virtue of the grace of God’s call: “Those whom he predestined he also called” (Rom 8:30; “He called you out from the darkness into is marvelous light” (1 Peter 2:9).
After this he mentions the rest of the people, by which I mean the faithful near to, but outside of the city proper, saying: “together with those who call on the name of our Lord Jesus Christ, in every place their and ours” by confessing the true faith: “All who call upon the name of the Lord shall be saved” (Joel 2:32 NAB, 3:5). “In every place both their and ours” refers to every place subject to the authority of the senders of the letter, for their subjection to the Bishop of Corinth did not mean they were free from the Apostle’s power; for they were more subject to the Apostles who was the one who had subjected them to the leaders in Corinth: “in every place of his dominion, O my soul, bless thou the Lord” (Psalm 103:22).
St Paul closes his greeting by wishing the m the beneficial gifts of God. He mentions first of all “grace,” by which men are set free from sin: : “Being justified by his grace as a gift” (Rom 3:24). He follows this with the wish of peace, which will come to completion in eternal beatitude: “He hath placed peace in thy borders” (Psalm 147:14); “my people shall sit in the beauty of peace” (Isa 32:18). These gifts contain all others.
The source of these gifts is Identified by Paul as being “from God our Father”: “Every best gift and every perfect gift is from above, coming down from the Father of lights” (James 1:17).
In addition the Apostle writes: “and from the Lord Jesus Christ,” the one “By whom he hath given us most great and precious promise” (2 Peter 1:4); “Grace and truth came through Jesus Christ” (John 1:17).
“From God our Father” can be taken as a reference to the Trinity Who created and adopted us as children. “The Lord Jesus Christ” is included not as a person in addition or superior to the three Divine Peersons, but on account of His divine Nature.
Or, “God our Father” can be a referenct to the person of the Father: “I ascend to my Father and to your Father, to my God and to your God” (John 20:17). “The Lord Jesus Christ”would then indicate the person of the Son. The Holy Ghost is not named for He is the bond of the Father and the Son, and is understood though not mentioned; or because He is given by both, His being given indicated by the gifts of “grace” and “peace” which are attributed as given by the Holy Ghost: “But all these things, one and the same Spirit worketh” (1 Cor 12:11).