It is an important hermeneutical rule that scripture interprets scripture. This makes Matthew 19:4-5 (also Mark 10:6-8) devastating to any Christian who claims Genesis should not be interpreted as a historical narrative.
The first reason for this is that Genesis is cited as the foundation for another major doctrine; that of marriage. Marriage is not arbitrary. It was designed by God in the beginning, and it survived the fall. Put simply, we get married, i.e. we partner a man and a woman together in a sexual union for life, because that is how God created human beings in the beginning, which the rest of the chapter being quoted says happened a mere 6 days after the initial creation of the earth.
The second is that it is Jesus quoting it. In other words, not even a "red letter Christian" can make the claim that Jesus didn't say this in an attempt to invalidate it. Not that I give any credibility to such a reckless and blasphemous theology, but the fact that the only way to doubt this is to doubt Jesus should clue you in to the fact that a non-historical reading of Genesis is the exact opposite of the Christian view.
Unfortunately, many Theistic Evolutionists tend to go the other way. Rather than repenting of their false view, they instead also reject or pervert the doctrine of marriage. This is why the Lord sternly warns us not to add to, or take from His word, lest we end up disobeying it. But to those who love the Lord, believe the Lord and seek to obey the Lord, a historical view of Genesis is the only consistent option.