Ephesians 2:19-21: "19 So then you are no longer strangers and aliens, but you are fellow citizens with the saints and members of the household of God, 20 built on the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone, 21 in whom the whole structure, being joined together, grows into a holy temple in the Lord."
Matthew 16:16-18: "16 Simon Peter replied, 'You are the Christ, the Son of the living God.' 17 And Jesus answered him, 'Blessed are you, Simon Bar-Jonah! For flesh and blood has not revealed this to you, but my Father who is in heaven. 18 And I tell you, you are Peter, and on this rock I will build my church, and the gates of hell shall not prevail against it.'"
Ephesians 4:3-6: "3 eager to maintain the unity of the Spirit in the bond of peace. 4 There is one body and one Spirit - just as you were called to the one hope that belongs to your call - 5 one Lord, one faith, one baptism, 6 one God and Father of all, who is over all and through all and in all."
Ephesians 4:15-16: "15 Rather, speaking the truth in love, we are to grow up in every way into him who is the head, into Christ, 16 from whom the whole body, joined and held together by every joint with which it is equipped, when each part is working properly, makes the body grow so that it builds itself up in love."
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Most of the cited passages appear in the first verse. The line "Lord Jesus Christ, the Church's head," comes from Ephesians 4:15-16, and the line "You are her one foundation" from Ephesians 2:19-21. The lines "Built on this rock secure, / Your Church shall endure" come from Matthew 16:16-18.
Ephesians 4:3-6 appears in the second verse: "O Lord, let this Your little flock... Continue in Your loving care, / True unity possessing." This may overlap a bit with "being joined together" in Ephesians 2:21 and "joined and held together" in Ephesians 4:16.
The line "Teach us to bear Your blessed cross" in the fourth verse may refer to Matthew 16:24 ("Then Jesus told his disciples, 'If anyone would come after me, let him deny himself and take up his cross and follow me.'") or Luke 9:23 ("And he said to all, 'If anyone would come after me, let him deny himself and take up his cross daily and follow me.'"), although the hymn has "Your blessed cross" where these passages have "his cross."
