In the beginning God created the heaven and the earth. -- Genesis 1:1Some Christians believe there was a long gap (perhaps as long as 4.6 billion years) between the first two verses of Genesis. During this time there was a war in heaven, demons were cast down to earth, and nature was corrupted through demonic activity.
And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters. -- Genesis 1:2
This interpretation addresses two problems caused by modern science: the age of the earth and the nature of nature. A straightforward reading of Genesis indicates that the earth is only about 6000 years old, not the 4.6 billion that science has found it to be. And disease, suffering, death, predators, and parasites are found throughout the living world, yet all were supposedly created by a kind and loving God. The gap theory allows Mother Nature to be both old and nasty, without casting blame on God or the Bible.
Needless to say, the gap theory is controversial among Bible-believers. Here are some links to believers on both sides.