Why do Christians become Christians?

[Mudhammam]

So your answer is that more and more people every year, for 2000 years, are either 1) not concerned about the truth, 2) deceived and fail to detect the deception. 

Yes.

Your statement that Christianity contains "overwhelming examples of division, egotism, theological hatreds, and falsehoods, which tend to be indistinguishable from the utterly delusional" does not line up with the teachings of the NT (and therefore not Christian).

Sure it does. First and foremost, the NT wholly and devoutly sanctions the Old Testament as expressive of God's holy thought on terrestrial matters, which includes such gems of bigotry as Psalm 14:1 and the countless instances in which apostates and blasphemers are sentenced to be executed. This mindset is clearly seen to carry over into the New Law, where Jesus and his followers condemned all those who disbelieve in God or the Christ to eternal torment, or as Paul puts it: "Neither the sexually immoral, nor idolaters, nor adulterers, nor men who submit to nor perform homosexual acts, nor thieves, nor the greedy, nor drunkards, nor verbal abusers, nor swindlers, will inherit the kingdom of God. And that is what some of you were. But you were washed, you were sanctified, you were justified, in the name of the Lord Jesus Christ and by the Spirit of our God." So, on top of the fact that these bigoted texts found in the OT and NT equate atheism with total wickedness and greediness/thievery/swindling/verbal abuse with homosexuality (the author clearly knows a thing or two about verbal abuse), it also condemns anyone who rejects the proclaimed "anointed one" to everlasting suffering after death. What you should have said, then, is that I meant this:

So, in fact you are talking about individuals who exhibit these qualities inspired by what it means to be a Christian according to the Old and New Testaments.

In general, you are ascribing motives and reasons for people's beliefs when in reality, you do not and cannot know.

I can know about as well as you can, as you clearly presumed to know in the OP.