I'd say John 3:16 sums it up pretty well. That scripture alone says what it takes to be saved.
And as far as baptism goes:
If baptism is all it takes, then a person could get dunked, and just go on doing whatever they wanted, with no consequences.
What is flesh, is flesh. To be born in the flesh, well, that is what we are when we come into this world. To be born of the spirt takes an action by us, and that is taking Jesus into your heart.
I think one of the biggest problems mankind has is, they can't comprehend a REAL "free gift". God gives us the free gift of salvation if we accept it. And that is all it takes, acceptance. How many of us can give a gift, and expect NOTHING in return? Even if all we expect is a "thank you"?
I sum it up this way: God's FREE GIFT to us is salvation, our "gift" back is what we do with it.
And that also goes with the "store your treasures up in Heaven" scripture. If you do nothing with your salvation other then taking the free gift, when you get to Heaven you won't get the treasures you could have received had you used your gift the way God wanted you to.
I remember back just after I got saved. I had met up with an old and close friend of mine from high school. I was afraid of what he would think of me if I told him about how I had got saved. That he'd think I had lost my mind.
On the day he was going to go back home to California, where he had moved to, I sat down on a curb with him, and told him about Jesus. I was scared to death! I told him "I always said how I loved you as a friend, and if I do, I wouldn't be much of a friend if I didn't tell you how to be saved." I didn't look at him while I was saying all this. When I finally DID get the courage to look at him, tears were flowing down his face and he said "Al, if you wouldn't have told me what you just did, you really wouldn't be my friend." He accepted Christ while sitting on that curb.
What a BLESSING it turned out to be for ME! Had I let my fear control me, I would have lost out on that moment.