Whenever there is disunity among believers, the Holy Spirit is not involved. Believers can step outside of the Holy Spirit in their flesh and bring about disunity. But as long as they are led by the Holy Spirit they will follow peace with all men, particularly with their brothers In Christ. To remain in unity when there are theological differences we must focus on our Common Faith and submit ourselves to the Holy Spirit.
The unifier does not expect or want us to be unified with the world. As a matter of fact, we are instructed to:
→ love not the world
→ keep ourselves unspotted from the world
→ come out from among them and be separate.
We are to preach the Gospel to the world so that each person comes under the authority of the unifier by faith in Christ Jesus.