From the point of spiritual birth there will be diversity in disciples in knowledge, understanding, strength, ability, and maturity. Their justification is in being made right by an act of grace, not because they are right in all things. They are in the right because they are in Christ who is their righteousness, though they may not be right in all matters of faith. There is unity in the faith but diversity in matters of faith . Fellowship is not destroyed by failure to understand all the scriptures and to hold the perfect interpretation of them.
Fellowship is established when that element of the word called the gospel is believed and obeyed.
Fellowship is sustained with God and man by following the other teachings of the word.