What verses pertain to when the church began ?
Was it before the cross?
Was it Just after the cross ?
Was it Acts 2 ?
was it after Acts 2 ?
Well, Jesus spoke in Matthew 28 about the way to resolve disputes with a sinning brother in the local church. This was before acts.
It is a New Testament practice of discipline within a church that is a similar process to deuteronomy, with two or three gathered together to sort out a dispute within the congregation.
Also.. you have the disciples doing all the work of a new testament church before Acts.
So I think it's safe to conclude Jesus and His disciples were the first church.
Now. .. this church is not the 'every believer' entity.
Every believer began way way back in early Old Testament. In Genesis.
That's part of the Family of God, which is the triune God, angels and all believers living and dead.
So yeah.. the local church beginning with Jesus and His disciples before Pentecost.
The entity of every believer beginning with the first believers in the OT.
Kingdom of God.. widest circle
Family of God .. next circle within that.
The body of Christ.. the local NT church, within that.