First of all my resemblance to my father and siblings is just too strong for me not to be related.

Next, if I were to find out there was a god after all.... He or She woudl have a lot of explaining to do in order to satisfy my rational mind.

I would happily take a DNA test to confirm whether or not I am the biological child of my parents. I have various reasons to beleive that I am the biological child of them, however, a DNA test would sort that issue out once and for all. With regards to god, assuming that I know which god. I would go out of my way to understand that god as best as I could. Feel silly for writing that last sentance. Its like answering the question 'what would you do if you found out there was an invisible unicorn living on the moon that created us all, and decided whether we went to a heaven or a hell when we die'

If the people i call mom & dad raised me with love, what difference would DNA make (unless i guess serious genetic based illness was present). What a slap in the face to both adopters & adoptees that question is!
If some gawd walked in, it better be prepared to face my wrath, you stupid, do-nothing while people & animals suffer i should bow to you why, exactly?!!?

In response to the question about proof or parentage, my response would liken the idea to being brought up to believe in religion. As a naive, innocent child I would blindly believe what I'm told. As I learn logic, reasoning, and science, and I began to notice things like a parent having a cleft chin whereas I do not, a difference in skin tones, etc. etc, over time I would question the claim, mount the evidence for one way or the other, and make an educated conclusion.

An intelligent person brought up under any religion SHOULD do the same.

If I found there really was a "creator/god" I would be obliged to believe. Then there is the question of which god it is, highly doubtful it will be any of the gods proffered so far by man. Then is the question of did this god actually want belief/worship & if it actually deserved such. & THEN I have to figure if I am able to offer such worship. I'm a stubborn cuss, & a Yank at that. Really tough to "bend the knee" to anyone. If respect is actually due, I would need to be convinced, & not just by the act of creation itself (tho that may bring a sense of awe), & worship would be a much harder proposition!