It may be said that the words of Jesus meant
that even though He was the light, He granted
the disciples (and us) to be the light of the world.
[Matthew 5:14]. So also, as He was the Rock, He
granted the disciples (and us) to be the rocks or
foundation of the church.

The Bible teaches us that the Church is a living
temple built of living stones. Peter repeated the
prophets: "To whom coming, as unto a living
stone, disallowed indeed of men, but chosen of
God, and precious. Ye also, as lively stones, are
built up a spiritual house, and holy priesthood,
to offer up spiritual sacrifices, acceptable to
God by Jesus Christ" 1 Peter 2:4-5