Does knowledge make one a "Christian", or obedience?

Michael Williams here:

The simple definition of the term Christian is a person who believes in the teachings of Jesus Christ. ... [H]ow can someone be like Christ if they do not know even the simplest things that the Bible teaches about Him? ... The point to be made is that teaching and learning about Christ is a central element to someone being a Christian.

Were the disciples knowledgeable about the teachings of Jesus when they left all and followed him? If not, how can it be said that they were his disciples even though they were not at all like him? The point to be made is that they were his followers not because they knew anything but because they obeyed him.

The gnosticism underlying fundamentalism: Correct knowledge is essential to salvation

Not just knowledge, but correct knowledge.

Michael Williams says so twice so you get it, here:

[N]early 95% of the people who claim to be a Christian cannot articulate or answer simple questions correctly about how they know they are saved. ... Nearly 95% of the people who claim to be a Christian cannot articulate or answer simple questions correctly about how they know they are saved.