I spent the day yesterday in the prayer room at the Promise Keepers conference in Orlando where Christians from a variety of denominations were gathered to pray for the speakers, and for the souls of those present. Denominational bickering was set aside to join in agreement to pray for the souls of the lost, to pray for our country and for God's will to be done.
One word kept popping up in prayers and that word was unity. But, a unity based on what? 2 Chronicles details an alliance Jehoshaphat made with Ahab because as Jehoshaphat put it, "We are brothers". He married off his sons to Ahab's daughters who turned out more fervently pagan than their mother was. Jehoshaphat wanted a unity based on a physical relationship and valued unity over and above the truth. This unity he created destroyed his kingdom and set in motion generations of evil kings in Judah.
Take it easy! I am not saying that our denominational friends are evil in any way. Many of them may be Christians, but the unity they wanted was between Catholicism and Christianity. Catholicism teaches a works-based salvation through Mother Mary and her shared Co-Mediatrix work on the cross. Another group represented came from the Oneness Pentecostal church which teaches that Jesus and God are not One, but two gods.
In John 8:24, Jesus said that unless you believe that He is Who He claims to Be, that you will die in your sins. The identity of Christ is essential to your salvation because Jesus was not just a good man, not just a prophet, He is God in Flesh.
A unity that encourages ignoring such flagrantly false teachings is not a unity that God desires. Our unity must be based on the truth. There are two things that you cannot be wrong about and still be a Christian. The first is you cannot be wrong about who Jesus is. The second is you cannot be wrong about your salvation. Obedience is just as much a part of salvation than belief.
We can unite in prayers with some brethren, but with those that clearly teach contrary to the Bible in the two essentials, we cannot as Jehoshaphat did call them brothers.