When was the Church established and when did it begin?

It's establishment:

Matt. 16:18 — "I will build" (future tense)

Eph. 2:20 — "And are built upon the foundation of the apostles and prophets" (the church is built upon both apostles and prophets)

Acts 20:28 — "to fed the church of God, which he hath purchased with his own blood." (so Christ must die and shed His blood before the church can even commence)

It's beginning (empowered):

Acts 2:1 — "day of Pentecost... they were all with one accord in one place."

Acts 2:4 — "And they were filled with the Holy Ghost..."

Acts 2:41 — "Then they that gladly received his word were baptized..."

Acts 2:47 — "And the Lord added to the church daily such as should be saved."

Let us consider therefore an allegory of the Church:

1. Not Built Yet — The Blueprint

2. Built — The Foundation is Laid (Christ's Death and Resurrection)

3. Empowered — The House is Moved Into and Comes Alive (Day of Pentecost).

When Jesus said, "Follow me, and I will make you fishers of men," this was not the beginning of the Church. At that point, Jesus had not yet revealed the concept of the Church—He didn’t mention it until Matthew 16:18. This shows that the Church was not yet established, but part of a future plan.

Jesus chose to reveal the idea of the Church only after the disciples had grown in spiritual understanding, particularly after key events like the Transfiguration.

Hence, the mystery of the church (unknown) was revealed after the resurrection of Christ — Through divine revelation to the apostles, especially Paul (my gospel) — Empowered and made visible at Pentecost (Acts 2).

Illustrate:

Example (a)

Think of all the stages required to bring a house into existence: planning, clearing the land, laying the foundation, building the frame, adding the roof and windows, installing plumbing and wiring, finishing the interior, connecting power, and passing inspections—until finally, the house is ready to be lived in.

Example (b)

Another example is that of the church compared to a birth. The church "existed" in "embryonic form" in the Gospels, but it was birthed "kicked and screamin" at Pentecost.