When individual Jews and Gentiles become a Christian, they form one spiritual unit, which Paul describes in several ways. He calls this union a nation, the household of God and a temple. He says the apostles and prophets provide the foundation and Christ Jesus provides the cornerstone of this structure which is being built (Ephesians 2:20-22).
There are four components to this building. They are the apostles, the prophets, Christ Jesus Himself and Christians. When one contemplates these elements, one must conclude that the church is built upon the teachings of Jesus, along with what the apostles and prophets taught. Individual Christians are the “walls” of the structure.