I work as a lab technician and medicine is one of my many interests. A couple of years ago I read that If a person has a bone marrow transplant there DNA will change. This is so amazing to me that your actual DNA is changed.
I thought about this analogy of how when you accept Christ in your heart you will be changed.
Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new. 2 Corinthians 5:17