the case for a literal interpretation of Genesis

Many times on the inter-webs, I meet liberal Christians who think we should not take the bible literally or that some bible passages can only make sense as allegory. What they never tell us is when to read the bible allegorically and when to take it literally. There are many believers who say the bible has never been taken literally except by the fundamentalists, do such people see any difficulty a liberal reading of the bible would pose?

This christian however believes that taking Genesis, at least the first chapters as allegory poses more problems than it solves. One would hope that after coming to such an astute observation, he would maybe read some other book, maybe the Vedas or the Koran or the Gita, maybe their creation stories are a little better.

The believer identifies the following as arising from an allegorical reading of Genesis

Without Genesis, there is no:

Creation

Man

Gender roles

Fall

Sin

Need for redemption (and therefore no prophets or New Testament or gospel)

Covenant with Abraham

Land of Israel

Children of Israel (no lineage for Jesus Christ)

Tribes of Israel

Moses et cetera

This author goes further to ask if Genesis is allegory, how does one justify the existence of Jesus. The authors of his[Jesus] genealogy mention Adam. If Genesis is allegory, Adam is allegory and one can say with justice Jesus is allegory.

His/her solution is to believe in King James Bible as literal. There is no changing their mind.

Do other believers see a problem in taking Genesis as allegory and how do they resolve the issue when they arrive in the New Testament and Jesus several mentions of Adam and Eve. Can the bible be saved by holding both as allegory and as literal? IS this a viable position or is it everywhere beset with difficulties?