What does it take to be a christian?

I've been kinda down for a few days, and today I realized I want to believe and accept God into my heart, I've been calling myself an atheist, but now I accept that I was just doing that because I was a cynical person, my cynism was all I had, that and my narcissism, but I don't want to be like that anymore. It has been a long time since I last said that I believed in a God, probably the last time i was 14 years old, im 22 right now. I didn't know who to turn to, because most of my friends happened to have the same cynical way of thinking, and they made fun of christians as well, this is the only place that I know I can get answers right away, so please give me some advice. I'd appreciate it.