Does It Make sence

A Lab Scientist in fact The HOD of that department (Catholic) was giving a presentation and said, ' there is no way you can be born AS and a Man of God prays for you and when you go back to check it has changed to AA.
My question is ' do you believe in Miracles' answer is yes yet you believe that the Blood Group that God made HE cannot change it if need be?

Abeg, somebody help 'cos i don't understand.