Galatians 3:26-27: "26 for in Christ Jesus you are all sons of God, through faith. 27 For as many of you as were baptized into Christ have put on Christ."
Romans 6:3: "Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death?"
Luke 2:29-32: "29 'Lord, now you are letting your servant depart in peace, according to your word; 30 for my eyes have seen your salvation 31 that you have prepared in the presence of all peoples, 32 a light for revelation to the Gentiles, and for glory to your people Israel.'"
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The passage from Galatians appears at the beginning of the first verse: "Once in the blest baptismal waters / I put on Christ and made Him mine."
Romans 6:3 seems to be the basis for the lines "And thus I live in God contented / And die without a thought of fear" at the beginning of the third verse.
The hymn's refrain ("O God, for Jesus' sake I pray / Your peace may bless my dying day.") is drawn from Luke 2:29-32.