I don't believe that what makes someone a Christian is what church has on its records their membership. I also don't believe that what makes someone not a Christian is whether or not their name is on any church's membership records at all.
Being a Christian is about character and behavior; character whose content includes loving our neighbor and striving for peace, at the same time standing on a firm foundation of true principles. And even though a Christian must stand firm, it's not his place to forcefully interfere with another's freedom of choice in behaving un-Christian-like. It's also not a Christian's place to hate or to show hate to others. Jesus Christ, while on Earth, had among his company both saints and sinners. He said, "a new commandment I give unto you, that ye love one another; as I have loved you, that ye also love one another. By this shall all men know that ye are my disciples, if ye have love one to another." This is what it means to be a Christian.
It's unfortunate what some have done in the name of Christ. Whether done in the name of Christ or not, the source of such evils has not been the Jesus Christ that I, and so many others who strive to do good and to serve others, believe in and follow. Anything can be perverted to justify what only can be attributed to human weakness.
As a seeker of truth, it's my responsibility to discern logically what I encounter in life. Truth is often times made plain, and more often made hidden. But it can be found and should be looked for, and that quest should be taken carefully and intelligently. We shouldn't allow others to deceive us into believing something that isn't true even though it sounds good. Many times the truth hurts and pierces us "to the very soul, and [can] cause [our] hearts to burn."
I believe that what I have found in my quest for truth is just that, truth. And I believe that others can find it too. I also believe the words of Christ when he said, "If ye continue in my word, then are ye me disciples indeed; and ye shall know the truth, and the truth shall make you free."