1 Corinthians 1:4

I thank my God always on your behalf
Now follows a thanksgiving for various blessings bestowed upon this church, which is a proof of the apostle's great affection for it, and how much its welfare lay at his heart. The object of thanksgiving is God, for as he is the author of all mercies, the glory and praise of them ought to be given to him. The apostle styles him "my God", to distinguish him from others; and to express his faith of interest in him; and to observe to this church, that all the good things they enjoyed came from him, who was his God and their God, his Father and their Father; and for which reason he returned thanks to him for them, and by so doing set them an example: the persons on whose behalf he gave thanks were not at this time himself and Sosthenes, but the members of the church at Corinth; and the continuance of his thankfulness for them, is "always", as often as he went to the throne of grace, or at any other time thought of them: what he particularly gives thanks to God for in this verse is,

for the grace which is given you by Jesus Christ:
and includes all sorts of grace, adopting, justifying, pardoning, regenerating, and sanctifying grace; every particular grace of the Spirit, as faith, repentance, hope, love, fear, humility, self-denial all are gifts of God, and entirely owing to his free grace, and not to man's free will and power, or to any merits of his; and all come through the hands of Christ, and are given forth by him, as the Mediator of the covenant, and in consequence of his blood, righteousness, sacrifice, and merit.