Mark 16:9-13

Mark 16:9-13. Now when Jesus was risen early the first day of the week, he appeared first to Mary Magdalene, out of whom he had cast seven devils. And she went and told them that had been with him, as they mourned and wept. And they, when they had heard that he was alive, and had been seen of her, believed not. After that he appeared in another form unto two of them, as they walked, and went into the country. And they went and told it unto the residue: neither believed they them.

Unbelief is very hard to kill, even in hearts that are right with God; so we need not wonder that divine grace is required to expel unbelief from the hearts of the unregenerate.