I have nothing against Objectivism. See my homepage.
You imply that an Objectivist could never be charitable. I imply no such thing. You have inferred it, and you are mistaken. Charity can be selfish -- properly understood. Jesus' view is actually closer to Kant's: he admonishes people from taking satisfaction of the kind you write of in charitable work. Nevertheless, Rand would be horrified at the thought that an Objectivist could be a Christian. If you had ever read any of her writings, you would know this. Read my other posts, which quote her at length if you want to disabuse yourself of your silly ideas about Rand.
The answers are John - 3.16 and belief in the concept of man as a heroic being, with his own happiness as the moral purpose of his life, with productive achievement as his noblest activity, and reason as his only absolute.
Knowing the New Testament from Matthew to Revelation is not necessary to being a Christian any more than reading every work by and about Ayn Rand is a requirement for calling oneself an Objectivist.
I became a Christian in 1978. When I discovered Ayn Rand a few years later, I felt at that time that I had always been an Objectivist, because that fit how my brain is wired.
I have read, We the Living, Anthem, The Fountainhead, Atlas Shrugged and many other articles and excerpts of the The Objectivist Newsletter. I am on the email distribution of the The Objective Standard although not a current subscriber. I still get the requisite yearly copy as an enticement to subscribe. Being Christian is of the heart, being an Objectivist is of the mind.