First of all nobody claims the Bible is 100% literal, there are thousands of figurative examples given in the the Bible. I.e., Jesus was referred to as the "bread of Life", that doesn't mean He was actually a loaf of bread.
Furthermore...
The Bible is a story. It has a beginning, a middle, and predicted end. And as the story progresses things change (as would be expected). God chose Israel as His people, yet after continuous rejection culminating in the rejection of their Messiah God set aside Israel and turned to the gentiles through the apostle Paul. This new covenant is discussed in extreme detail in the New Testament but primarily in the Paul's epistles as he was the chosen apostle for that dispensation.
In conclusion... Christians don't become Jews because Jesus instructed them NOT TO through the apostle Paul. That doesn't make the things that happened before any less literal, instead it merely highlights how God works within the fabric of reality reacting and adjusting to man's obedience or disobedience.
There you go again...being all truthful...sheesh!