Make every effort to keep the unity of the Spirit through the bond of peace. There is one body and one Spirit— just as you were called to one hope when you were called— one Lord, one faith, one baptism; one God and Father of all, who is over all and through all and in all.

(Eph. 4:3-6)

1. Denominations do not "make every effort" to preserve the unity of the Spirit. Quite the contrary, they continue to multiply and "divide." Even the greatest leaders among them make no attempt to "heal the rift" between them.
2. Denominations teach that there are many bodies, not just one. They often use Jesus’ vine and branches illustration in Jn. 15. But Jesus was not talking about denominations in Jn. 15! He was talking about individuals like branches being nourished from one source—Jesus, who is like a vine.
3. Denominations teach different faiths. Some teach that certain things are sinful while others say those things are ok. Some teach that you have to do things that others say you do not have to do.
4. Denominations perform different baptisms—usually to become a member of their particular sect.

"But I don’t think like that and no one else in my church does either. We are just trying to go by the Bible, worship God, and please Him!"

Most Denominationalists have pure motives, but sincerity in practice will not make a wrong practice right. If you are part of a denomination, you need to get out of it and become part of the ONE true Body.

"My Denomination is PART of the ONE Body!"

1. Jesus established His church long before the first human denomination started. The ONE Body existed, as we’ve shown, united as one, long before the "other bodies" came along. Jesus did not establish a single denomination! Paul did not accept them and Jesus was against them, so how could they be part of His church, the ONE Body?
2. A "Divided" or Denominational Body of Christ is not possible. The Body of Christ was designed to be Non-Denominational. Look at this verse: