Romans 6:23

For the wages of sin is death; but the gift of God is eternal life through--"in" Jesus Christ our Lord--This concluding verse--as pointed as it is brief--contains the marrow, the most fine gold, of the Gospel. As the laborer is worthy of his hire, and feels it to be his due--his own of right--so is death the due of sin, the wages the sinner has well wrought for, his own. But "eternal life" is in no sense or degree the wages of our righteousness; we do nothing whatever to earn or become entitled to it, and never can: it is therefore, in the most absolute sense, "THE GIFT OF GOD." Grace reigns in the bestowal of it in every case, and that "in Jesus Christ our Lord," as the righteous Channel of it. In view of this, who that hath tasted that the Lord is gracious can refrain from saying, "Unto Him that loved us, and washed us from our sins in His own blood, and hath made us kings and priests unto God and His Father, to Him be glory and dominion for ever and ever. Amen!" (Rev 1:5-6).

— Jamieson-Fausset-Brown Commentary (public domain)