Galatians 4:19

τεκνία μου. This is an accusative in apposition to ὑμᾶς, not a vocative introducing a fresh appeal. It is clear from the addition of the connecting particle δέ after ἤθελον that that word begins a new sentence. τεκνία is usually a term of maternal endearment; and though addressed by John in his first Epistle to his children in Christ, is not used elsewhere by Paul, who prefers to address them as children (τέκνα), rather than as babes. But in this passage he is adopting the figure of a child-bearing mother; he is in travail for the spiritual birth of Christ within them (as he says), and straining all his powers to renew once more the spiritual life which had died in them until he could succeed in shaping their inner man afresh into the image of Christ.