Some thoughts on Matthew 19:4-6...
Just accepting the fact that these 3 verses are accurate, Holy Spirit inspired renditions of what Jesus said, leads us to 3 conclusions:
1. God created everything, including mankind, at the beginning. There was not millions of years, and then mankind. Man and woman, from the start. Jesus Himself confirmed the Genesis story of creation.
2. Jesus asks if they have not read that God "made them male and female...and the two shall become one flesh." Man and Wife, joined in marriage and life..let no man separate what God has joined together.
3. Jesus asks "Have you not read?", referring to the passages directly from Genesis in BOLD below. Later, the Pharisees state that it was Moses who was the writer, and Jesus does not correct them. Moses wrote Genesis, and the first 5 books of the Old Testament, as stated in the Bible itself.
I conclude, based on Jesus own comments, that these 3 statements need no further explanation, and are trustworthy.