There is always the possibility that her interest in you does not go beyond friendship. If you and she don't hit it off, that would be an unhappy outcome for you, but at least your problem would go away, and you won't have to spend the rest of your life wondering. The kind of prejudice your family feels won't change by itself. If you wait for that to happen, you'll both be old and never know if you belong together. If you and this girl do find love, then your father, as a minister and a Christian, will have to get over it.
Many many people marry for the wrong reasons.
Don't marry to please your parents. Marry to please yourself. The world is full of interracial marriages, interreligious marriages and all other kinds of marriages that parents would rather not deal with. Eventually though, most parents come around, especially when there are grandchildren to love. So if your parents have an unreasonable bias, don't perpetuate it by letting it rule your life.