As well as all the various idiot versions, there is also the really sophisticated version which goes, roughly:
1. Revelation tells us that the creation of the world happened recently - it is a requirement of faith to believe in the 4004 BC date.
2. We know that Adam was created and not born. However, since he was a complete and perfect man in all respects, he nonetheless had a navel as if he had been born, because otherwise he would not have been complete and perfect.
3. In precisely such a way, God will have created the world in such a way that it appears that it existed for a long time prior to 4004 and that life reached its current complexity by a long process of evolution through natural selection.
4. Deep time and evolution by natural selection are logical theories consistent with all the evidence - they are necessary parts of how the world looks. It was, however, created in 4004 BC and we know this because the bible tells us so.
5. God did not intend this as a test of our faith, though such a test it certainly is. He did it because the most logically consistent way to create a world is to make it look as if it had deep time and natural selection in it. God is above logic, but his universe is logical except where he intervenes by particular acts like the creation or miracles.
Philip Gosse, who came up with this or something like it in his book 'Omphalos', was a serious scientific observer and a very long way from being fool or knave. He was, unfortunately, a humourless fanatic when it came to matters of faith - but there is a certain elegance in the lunacy of his position which has been missed by his creationist successors.