What is the minimum amount of knowledge of Christ needed to be a Christian?
I'm not even sure I'm asking the right question. I'm a convinced Christian Universalist and I was recently having a debate with a militant Calvinist about Universalism, as well as what puts someone outside the faith. My dream goal would be to convince Calvinists that biblical Universalism is true, and for the ones that can't be convinced, at least convince them that Christian Universalists are at least Christian (and kudos to Redeemed Zoomer as a prominent example of a Calvinist who accepts Universalists as Christians, because he knows his history.)
At the end of my debate, I finally asked this Calvinist what denials of Christ's teachings or attributes would in their opinion put a person outside the faith. Their response was simply that the line was drawn when you create another god to suit your beliefs. This person puts Christian Universalists in this category, but did not elaborate further.
So, what defines a Christian? What puts someone outside the faith? The early Christians had little concept of the Trinity, yet we wouldn't say they were outside the faith. Peter the fisherman simply believed Jesus when He said "follow me." What about Oneness Pentecostals? What about LDS members? What is faith in Christ, and what is it not? So many Christians seem to put up arbitrary boundaries. Calvinists who say you can't be an Arminian. Christian Universalists who say you can't believe in "infernalism." Christians who say you MUST believe in the Trinity. These seem like extrabiblical qualifications for being considered a Christian. We are fallen people with fallen minds so none of us has perfect knowledge of God. What is the essential knowledge of Christ (apart from perfect knowledge) we need to have faith in Him?
The reason I'm asking is I'm not really sure myself. My old answer was "A Christian is someone who looks in faith in Christ, regardless of the extent of their knowledge about Him." This would include LDS members. But maybe my definition fails because theoretically you could call a statue on your nightstand "Jesus," have faith in it and still be called a Christian. And this obviously isn't true (then again what if you had a mental illness, so maybe).
No one has perfect knowledge of Jesus Christ. So what is the minimum knowledge required to be considered a Christian?