Religious people — even sincere Christian people — may divide themselves into various denominations or churches, but there is no indication in the Bible that God recognizes these divisions. Indeed, God makes it abundantly clear that in His sight there is but one Church, composed of all who truly trust in the Lord Jesus Christ as their Savior. In I Cor. 12:12,13 the Apostle Paul declares by divine inspiration:
“For as the body is one, and hath many members, and all the members of that one body, being many, are one body: so also is Christ:
“FOR BY ONE SPIRIT ARE WE ALL BAPTIZED INTO ONE BODY….”
Again, in Rom. 12:5, he says:
“SO WE, BEING MANY, ARE ONE BODY IN CHRIST, AND EVERY ONE MEMBERS ONE OF ANOTHER.”
Indeed, it is on the basis of the fact that there is but “one body” in God’s sight that He exhorts us to seek to “keep the unity of the Spirit”:
“ENDEAVORING TO KEEP THE UNITY OF THE SPIRIT IN THE BOND OF PEACE.
“THERE IS ONE BODY….” (Eph. 4:3,4).
How can we become members of that “one Body ,” the true Church? Ephesians 2 explains how Christ died for all, Jew and Gentile alike, “that He might reconcile both unto God in one body by the cross…” (Eph. 2:16). Indeed the Epistles of St. Paul show how God “hath concluded… all in unbelief that He might have mercy upon all” (Rom. 11:32), and offer to them reconciliation and salvation by grace through faith in Christ who died for our sins.
The question, then, is not: What church do you belong to? but, Do you belong to the Church, the Body of Christ, composed of all who have acknowledged themselves to be sinners in the sight of God and have trusted in Christ and His finished work for salvation? source