John Calvin Commentary Colossians 1:4

"having heard of your faith in Christ Jesus, and of the love which ye have toward all the saints," — Colossians 1:4 (ASV)

Having heard of your faith. This was a means of stirring up his love towards them, and his concern for their welfare, when he heard that they were distinguished by faith and love. And, unquestionably, gifts of God that are so excellent ought to have such an effect upon us as to stir us up to love them wherever they appear. He uses the expression, faith in Christ, so that we may always bear in mind that Christ is the proper object of faith.

He uses the expression, love towards the saints, not with the intention of excluding others, but because, to the degree that anyone is joined to us in God, we ought to embrace him more closely with special affection. True love, therefore, will extend to mankind universally, because they all are our flesh, and created in the image of God (Genesis 9:6); but in terms of degrees, it will begin with those who are of the household of faith (Galatians 6:10).