In essential beliefs… unity.
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. (Ephesians 4:4-6)
In non-essential beliefs… liberty.
Accept him whose faith is weak, without passing judgment on disputable matters. Who are you to judge someone else’s servant? To his own master he stands or falls. And he will stand, for the Lord is able to make him stand. So then, each of us will give an account of himself to God. So whatever you believe about these things keep between yourself and God. Blessed is the man who does not condemn himself by what he approves. (Romans 14:1, 4, 12, 22)
In all our beliefs… love.
If I have the gift of prophecy and can fathom all mysteries and all knowledge, and if I have a faith that can move mountains, but have not love, I am nothing. (1 Cor 13:2)