I need help with refutations for this

[TheDarkestOfAngels]

So you need help refuting these?
... I'll give it a shot.

1. I think belief in God is properly basic.

How is god 'properly basic' and why do you believe this to be the case?
Note that 'you' being your religious person who asked this.

2. The likelihood of my cognitive structure structure retaining true beliefs is greater than on theism, than given atheism).

a few problems:
The "true beliefs" and your "congnitive structure" and its method of retention of "True Beliefs" holds exactly as true for every belief, not just one given belief.
As such, no belief can be 'true' based on your cognative ability to "retain it."

This has entirely to do with how one is raised into a particular belief (or by not being raised into a belief at all) than one's natural state of mind. There is no 'likelyhood' in this - it's basic child psychology in that if you raise a child to believe something, that child retains that knowledge.

This is to say that if your religious friend were raised by a muslim family, he would just as likely be muslim by now instead of christian, meaning that #2 is entirely wrong.
There is no 'chance' involved, his 'cognative structure retaining true beliefs' is entirely gibberish and an attempt to sound smarter than he really is when all it really is essentially boils down to how a person is raised and what philosophies he's exposed to.

And for Christian theism in particularly:
3. Argument that God is not a unitarian God.

Based on what, exactly?
There is no evidence, anywhere, that such a being ever existed or influenced human or universal action that hasn't been explained by human scientific standards (which involves actual research and observations and so on).

4. The Resurrection as the best explanation of certain facts about the historical Jesus.

What historical Jesus?

5. Religious experience.

Members of any and every religion often have those. It doesn't make those religions legitimate and 'religious experience' isn't even necessary a sign of relgion being true - especially considering that two religious experiences can often contradict one another and often coincide with the religious faith of the one having the experience. Which is to say, that if your faith is the true faith then how do members of other contradictory faiths to yours (islam, buddism, and so forth) have religious experience that coincides with their faith and not necessarily yours?
If there is only one truth in the universe, then what does the religious experiences of others mean?

(I would expect him to say something along the lines of 'the devil did it' or 'god works in mysterious ways' - both of which are meaningless answers to handwave the thoughts away.)

now i do not have the knowledge to refute these except the 5th one, so i need some help to understand and perhaps refute this.

It's not about the knowledge you have, but asking the right questions.
Specific questions can give you the proper direction in order to find answers.