Church: Is it identified by prophecy?
Let's think for a moment. God, (who sent his Son to die for the sins of mankind, and through that death, purchased the church with his own blood, Acts 20:28) would surely make known to man all about that church. God did make known all about the church; it was prophesied about in the Old Testament and established in the New Testament.
In order to come to an understanding of the Lord's church, it is most important that one clears his mind of the denominational concept of the church. Jesus did not build a denomination of any kind, he built His church. It was established on Pentecost, Acts 2, almost two thousand years ago and still is in existence today. No denomination can trace their beginning back that far.
In Isaiah 2:3 we have a prophecy concerning the church which was fulfilled in Acts 2. It reads, "And it shall come to pass in the last days, that the mountain of the Lord's house shall be established in the top of the mountains, and shall be exalted above the hills; and all nations shall flow unto it". A brief look at some of the terms used in this prophecy will be helpful in understanding the church's beginning.
The phrase, "last days", is a reference to what is known as the Christian age. The Hebrew writer in Heb. 1:1-2 verifies this when he says "God ....hath in these last days spoken unto us by his Son". Peter, in his sermon recorded in Acts 2, identifies what was taking place as happening in the "last days" by quoting Joel the prophet. Peter said, Acts 2:16, 17 "But this is that which was spoken by the prophet Joel; And it shall come to pass in the last days". Also, the words "this is that" pertain to the prophecy of Isaiah 2:3, both alluding to the beginning of the Lord's church.
Isaiah speaks of the "mountain of the Lord's house" that will be established in the last days. The Lord's house is identified as the church by Paul in I Timothy 3:15. It reads, "But if I tarry long, that thou mayest know how thou oughtest to behave thyself in the house of God, which is the church of the living God, the pillar and ground of the truth".
Isaiah mentions, also, that "all nations shall flow unto it". Under the old covenant only the Jews were God's chosen people, but the time was coming when people of every nation could be united as one people of God. This happens in the church where both Jew and Gentiles worship God together as "one new man", Eph. 2:15. So in these last days, in the church, Christ reconciles "both (Jew and Gentile, all nations) unto God in one body (church) by the cross", Eph. 2:16.
The church, therefore, is identified by prophecy having begun on Pentecost as recorded in Acts chapter 2.