It may or may not be a surprise to you but bible believing Christians actually have a number of options when it comes to understanding Genesis 1 and 2 and how God created the cosmos. I'm open to a couple of the options as being more legitimate than others but there is one that makes most sense to me. Most biblical scholars are the same; they'll have a theory that will resonate with them and their study but will hold it lightly and graciously. There are of course biblical scholars in each of the various camps that refute all the other options as illegitimate, so it is still a contentious issue. Recently two of the church's foremost Old Testament scholars had to resign their positions in their respective seminaries over their beliefs and speaking out about the issue.
Here are five options, two are obviously not tenable as Christians. The other three are not necessarily contrary to scripture.
Special creation - the belief that the universe and life suddenly sprang into existence at the word of God. Most often this theory reads Genesis 1 and 2 as literal creation accounts.
Progressive creation - the belief that God instantaneously created new forms of life, but periodically over 100's of millions of years.
Theistic evolution - or similarly evolutionary creation, the belief that God created the cosmos through and by means of evolution. Evolution is a natural process within God's creation.
Intelligent design - the belief that certain aspects of the universe are best explained by an intelligent cause. Here though the source of the design is not defined and is not defined necessarily as the Christian God.
Evolution - that after a big bang the world evolved out of nothing into its reality today through random and natural selection.