Most Christians are ‘Young Earth Creationists’, who believe God created everything instantly out of nothing all in a matter of six days, some 6000 years ago. According to this view, about six to ten thousand years ago God spoke everything into being in six literal sun days and then rested on the seventh twenty four hour period.
Secular Evolutionists see the whole of existence as purely material with "matter" as eternally existent and all of the galaxies and life itself coming into being by accident over many millions of years. However Scientists are now finding that the universe in which we live is like a diamond studded Rolex, except the universe is even more precisely designed than the watch. In fact, the universe is specifically tweaked to enable life on earth. A Planet with scores of improbable and inter-dependent life- supporting conditions that make it a tiny oasis in a vast and hostile universe. The extent of the universe’s fine-tuning makes the Anthropic Principle perhaps the most powerful argument for the existence of God.
See Anthropic Principles
Most Christians believe that a literal 6 day creation is the most clear and simple interpretation of Genesis and other scriptures that speak of creation and the 6 days thereof. That both the young and old earth theory is possible, but lean toward a young-earth view for many reasons:
See Evidence For A Young Earth
However as said by Dale Tooley
there are those Christians who believe that the Genesis account of creation does not imply that the days referred to are six literal consecutive 24-hour days and that that no case can be made from the original languages to favor a young universe/earth interpretation. That the universe may be, in fact, millions, if not billions, of years old. And there is a fourth view (one that many people do not subscribe to) called Progressive Creationism which lies in between Theistic Evolution and Young Earth Creationism, drawing some points from both but always insisting on the input of intelligent design.
It agrees with the former in believing that there was a much longer time frame than six twenty-four hour periods and holds that each new life form was not, necessarily, created out of nothing, or out of previously non-living material. Or at least that the "template" of previously existing life is used again - with adjustments. It agrees with the latter, not only in affirming the verbal inspiration of the Bible, but that God was present at every stage of the creation of life and that every new life form was a deliberate and miraculous act of God. (Intelligent Life In Progressive Creationism. Dale Tooley
TO BE CONTINUED