Among several others, two of the stronger arguments that serve as evidence are the arguments for the existence of 'logic' and 'morality.'
Erg. I think we need a sticky thread for the "morality" argument. It's so lame.
Christians focus on how morality is cross cultural, to prove their point; but in order to really prove their point,
they have to show how morality cannot be derived from a set of general, selfish preservation principles that most tribal species seem to agree upon, because they simply have to, to be a tribe.
When I thought more about which "moral" principles are compulsory to adhere to, I found that only murder and theft are semi-solid. There is no cross-cultural agreement on how to marry women, or how much you can lie, simply because there is no compelling evolutionary logic to base it on. Most animals fight for the right to mate multiple females, and this is in Islam and many tribal cultures. Marriage laws are a premiere moral of Judaism, yet they have no liberal ethical basis, only an evolutionary one.
Then, a contra argument: if it's bad to kill, then why does "God" ordain death for trivial offenses? Then, why does Jesus come along and negate it? Even the murder principle is flexible in religion.
There are definitely morals that come from God:
those which make no sense. Examples:
Killing people for doing something on a Saturday
Beard and hair laws
Persecution of homosexuals
Laws against nakedness
Divorce laws
Worship of idols
It's only the crap non-cross-cultural laws which truly come from God; the rest we have to follow to survive.
The absurdity of the morals argument, is that Christians seem to know what most of the morals are for. If so, then they can be derived from "common sense". The ones they can't explain are the shit that come from non-commonsense, ie God.