1 Corinthians 15:17-20: "17 And if Christ has not been raised, your faith is futile and you are still in your sins. 18 Then those also who have fallen asleep in Christ have perished. 19 If in Christ we have hope in this life only, we are of all people most to be pitied.
"20 But in fact Christ has been raised from the dead, the firstfruits of those who have fallen asleep."
Isaiah 26:19: "Your dead shall live; their bodies shall rise. You who dwell in the dust, awake and sing for joy! For your dew is a dew of light, and the earth will give birth to the dead."
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1 Corinthians 15:17-20 seems to be the principal source. "Christ has been raised from the dead" appears at the very beginning of the hymn: "Christ is arisen / From the grave's dark prison," and "And if Christ has not been raised" appears in the second verse: "Were Christ not arisen, / Then death were still our prison."
Along with connecting to the theme of resurrection, the verse from Isaiah appears in the line "So let our joy rise full and free" in the first verse and "Now let our joy rise full and free" in the third.
Along with connecting to the theme of resurrection, the verse from Isaiah appears in the line "So let our joy rise full and free" in the first verse and "Now let our joy rise full and free" in the third.