> It must be difficult to feel comforted by your science.
It is not the purpose of science to provide comfort in the way you suggest. It provides answers. Sometimes they are comforting. Sometimes they are not.
> How do you know what you should be happy about or what to be sad about? Who sets the standard?
I do. Don't you set your own standards of what makes you happy or sad? Or do you have to keep a chart with you at all times?
> Whether you believe in Him or not is inconsequential to His existence. It is, however, consequential to your salvation.
Pure supposition.
God sets the standards by which we should live. Do unto others and so forth, in addition to the commandments. God stamps on everyone's heart his law and that's why children know instinctively what's right or wrong. In a way, I consider it our conscience. But, this is my belief based on a life that has been, let's say, quite active. I thought a lot of things that made me "happy" - when I was satisfied, i.e., thin enough, enough money, better clothes, better car, etc. It took more and more to make me happy. After awhile, I ended up lost and confused that why, since I have everything I want, am I not happy. I did some soul-searching and went back to my Catholic upbringing. I prayed for God to let me see the light (I know, don't say it). And He did. Since that time, true happiness for me can only be found through the wisdom of God and by His grace. It sounds strange and even primordial sometimes, but its too true to deny for me. It's like a complete happiness or content that is thick and full rather than hollow self-indulgence that is short-lived and bitter.
So yes, I have free will to choose if I want to live by God's standard or a worldly standard. Tried one, didn't work. The other, absolutely and completely worked for me.