When Jesus told Peter, "And upon this rock I will build my church" (Matthew 16:18), the "rock" He referred to is best understood in the context of Peter’s confession of faith and the broader teachings of Scripture. Here’s a breakdown:

1. Peter’s Confession of Faith

Just prior to this statement, Peter declared, “You are the Christ, the Son of the living God” (Matthew 16:16).

The "rock" is Peter’s confession that Jesus is the Messiah and the Son of God. This faith in Christ is the foundational truth upon which the church is built.

2. Christ as the True Rock

Throughout Scripture, Jesus Himself is repeatedly referred to as the "rock" or cornerstone:

“For no one can lay a foundation other than that which is laid, which is Jesus Christ” (1 Corinthians 3:11).

“The stone that the builders rejected has become the cornerstone” (Psalm 118:22; Ephesians 2:20).

“That rock was Christ” (1 Corinthians 10:4).

Thus, the ultimate "rock" is Christ Himself.

3. Peter’s Role

The Greek wordplay in this passage is significant. Jesus says:

"You are Peter (Πέτρος, Petros, meaning ‘stone’), and on this rock (πέτρα, petra, meaning ‘large rock or bedrock’) I will build my church."

Peter (as an apostle) plays a foundational role in the church, but the "rock" is not Peter himself, as he is a fallible man. Instead, his role is tied to proclaiming the truth of Christ, the true foundation.

4. The Church’s Foundation

The church is built upon the apostles and prophets with Jesus as the cornerstone (Ephesians 2:20). The "rock" signifies the truth of Christ’s identity and mission, revealed to Peter by God (Matthew 16:17).

Conclusion

The "rock" Jesus referred to is the truth that He is the Christ, the Son of God. While Peter was instrumental in the early church, Christ Himself remains the ultimate foundation and cornerstone upon which the church is built. This interpretation aligns with the rest of Scripture, which consistently points to Christ as the unshakable foundation.