Lets say I believe in God. How do I decide which God to believe in? How do you know Jesus is the way?

This is a commonly asked question. Look at these very wonderful answers to this very good question.

Which God is true?
http://www.answering-islam.de/Main/Shamoun/true_seal.htm
http://www.speroforum.com/site/article.asp?idCategory=34&idsub=127&id=3851
http://www.abrahamic-faith.com/shamoun/Is_Muhammad_a_true_Prophet_of_God.html
http://www.creeds.net/ancient/nicene.htm
http://www.bible.ca/g-Christ-gods-only-son.htm
http://www.qhpress.org/quakerpages/qhoa/crispq3a.htm
http://www.carm.org/jw/John17_3.htm
http://www.catholic.com/library/One_True_God.asp
http://www.everystudent.com/wires/real.html
http://www.gotquestions.org/is-God-real.html