In the sixth verse, the text here is "Preserve our faith our whole life through." "Whole" is sung with a melisma (G F), musically giving a sense of that entirety.
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I also noticed a Biblical source I'd missed when I wrote about the hymn a few years ago. The fourth verse mentions "The bright sword of Your mighty Word," which comes from part of Ephesians 6:17: "the sword of the Spirit, which is the word of God."