How can a Christian reject part of the Bible and still call themselves a Christian?

[EvolutionKills]

I had a conversation with Christian girl yesterday and it randomly led to the subject of homosexuality.
She believes that it is perfectly acceptable to be a homosexual because you should be able to love anyone you want.
I asked her how she could say that and call herself a Christian. She became iritated. I pointed out that her Bible clearly states that it is an abomination. She finally said " I don't care what it says" and ended the conversation. The stress caused by the cognitive dissonance was pretty high.
I find Christians do this a lot. They reject what they don't like in the Bible.

They have to, because nobody can follow the entire book to-the-letter since it is a self contradictory mess.

Are we pre-tribulation or post-tribulation?

Are we saved through works or faith alone?

Is the Law still to be upheld or not?

Should we hate and kill homosexuals or love them as our neighbors?

Just about any position anyone would care to take on just about any subject, you'll be able to find and quote a Bible passage to support your stance. This is incidentally just what one would expect from a book of cobbled together, man made, and edited myths.