The Apostle Paul
1 Corinthians 1:9BSB·traditional attribution

God, who has called you into fellowship with His Son Jesus Christ our Lord, is faithful.

John Calvin Reformed @genevareformer

9. God is faithful When the Scripture speaks of God as faithful the meaning in many cases is, that in God there is steadfastness and evenness of tenor, so that what he begins he prosecutes to the end, Calvin probably refers to the following (among other) passagess: — 1 Thessalonians 5:24; 2 Thessalonians 3:3; Hebrews 10:23.

Matthew Henry Presbyterian @wholebiblehenry

We have here the apostle's preface to his whole epistle, in which we may take notice, I. Of the inscription, in which, according to the custom of writing letters then, the name of the person by whom it was written and the persons to whom it was written are both inserted. 1.

Commenting on 1 Corinthians 1:1-9

John Gill Reformed Baptist @doctorgill

God is faithful, by whom ye were called,.... These words contain arguments, assuring the saints of their confirmation in grace, and of their being preserved blameless to the day of Christ, taken from the faithfulness of God, who is always true to his promises: whatever he has said, he will do it; he will never suffer his faithfulness to fail; and since he has made...