I know god exists because...
I have this feeling inside me.
This won't do as the followers of all the other religions have that feeling too.
All those other Christians can't be wrong.
This works equally well for the multitude of conflicting religions. They are just as sure as you are. In fact most of the Christians believe a different version and think that you have it wrong.
The Bible says so.
If you want to claim the Bible is the word of God then you have to explain the contradictions. If you want to say that only parts of it are true then you have to come up with a reason to believe one part and not another. Remember that the other Christian Religions claim the Bible too. They are just as sure about the true meaning.
There has to be something that made us.
That's a guess not a proven statement, but you know you could be right. However that something could be Allah, Aliens or Manitou - the god of the Native American Algonquin tribes. You have no basis for claiming it is your god and for listing his wants and needs.