As soon as you let humans into anything, you are going to have divisions, disagreements, pulling and tugging.
Its a human thing. Even something as relatively straightforward as the Bible, whoever reads it, someone else will quibble about some minor issue. Humans are just that way.
But just as God gives us grace, we need to extend grace to each other. And we need to keep a sense of proportion. Some disagreements are important; some are not. Some are worth separating over as the Holy Spirit leads and some simply are not. If you can forgive your brother’s doctrinal shortcomings in areas that are not make-or-break you also trust that God will overlook yours, which you surely will have. The body of Christ is a big noisy family; we are going to be arguing with one another all the way to the grave and, who knows, right on through eternity. God made us this way, I suspect he is used to us.
Paul rebuked Peter a few times.
Salvation should be straight forward and agreed to by all Christians though.