what is necessary to believe to be called Christian.
My opinion stated:
In the beginning?
1 Corinthians 15:1-7.
Overall?
Matthew 4:4, Luke 4:4.
To me, one cannot be a child of the living God without growth in both grace and knowledge.
One cannot be a child of God without being led of the Holy Spirit ( Romans 8:9-17 ).
Please keep in mind that I see the Bible teaching that as babes in Christ, we will fight amongst each other...
We can be and are "carnal" in the sense that we are not grown into maturity as believers, and can walk
as unbelieving men ( 1 Corinthians 3:1-4 ), even though we are not.
Part of that growth in grace includes seeing the fruit of the Spirit ( Galatians 5:22-23 ) in one's life.
If one continues to see the works of the flesh ( Galatians 5:19-21 ) dominate their lives over a long period, then I don't see how they can be saved.
If one is not being led into all truth and continuing in His word over that same long period, then I equally do not believe that that person is saved.
Growth takes time...
A lot of it, if my understanding on the subject is correct.
That growth relies on 1 Peter 2:2 and 2 Timothy 2:15...
His word and constant study of it are vital for our growth, spiritually.
That said, it would be wrong for me to expect even "middle aged" Christians to never get angry or to have heated disagreements.
But I should be able to expect those who name the name of Christ to at least be cordial, at some point in their lives, in their discussions.
Finally, we as believers should be able to one day come into the unity of the faith...
And I don't mean in the next life, as I see nowhere in Scripture that that is when that is supposed to occur.
Rather, I see a lot of people simply assuming that.