That is an awesome question Kiwi, and one that is going to be explored in the seasons to come. Religion, even if one isn't religious, plays apart in all of our lives. Some people justify their very existence on the depth of their faith, while others base their fate on justifiation of their actions. Either way, Lost points to a numerical map of everyones life, where fate and faith are running neck and neck and only the passion of either will decide the outcome.
Jack has been the man of science, and he's been a man of faith, they showed us both sides with his many flashbacks, but now he must choose the side which benefits both paths of life. The flash-forward we saw was a decision weighing too much to one passion, and therefore an imbalanced outcome. Hopefully, eventually, like us all, he choose moderation.

Being a Man of Faith...means many things. One of them yes being God. There are many kinds of ways of being a believer in Faith. You can have faith in your friends and family, Faith in a co-worker. Faith in yourself, but what it all comes down to is that to have faith in anything whether it be God or someone or something else it comes from a Higher Power. The word Faith is a powerful word in itself. To have faith in anything or anyone requires great strength and trust.

I believe that Faith and Science go hand in hand. So for Jack to be a man of Faith? Sure!!! When he looked up to the sky and and said forgive me. At this point his faith was with God.

Let me ask you this question, "Is a man of Science, just a believer in science?" It can go both ways.

If you ever get a chance watch the movie "Contact" with Jodie Foster and Matthew McCaughney, if you already have well its the same thing she believed in Aliens and then became a believer in faith.

It is a very good movie.

I believe that each one of the Losties and even the others believe in something of a higher power. Regardless all the mysterious and strangeness of the island there too is a higher power, whether it is the smoke monster or Jacob, or mayble Jacob is the smoke monster....we do not know.

Faith is the basis of our lives each and everyone of us. Regardless what believe in.

Have a nice day!

contact was good. and Gary Busey's crazy son is in it too....

and also, dont confuse faith with what limp bizkit screamed