EXPERIENCE and DOMINION
John 1:12 "But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name:" (KJV)
If you can convince someone into Christianity, they can be convinced out of it, but an encounter can never be erased.
Moses was alerted to something out of the ordinary - a burning bush. God told Moses that with signs and wonders, he will deliver God's people out of bondage. Moses tells the Egyptians that "I AM" sent him, the God of Abraham. Moses was enthroned by heaven to take on the throne of the world.
It was by Power of Attorney that Joshua had the ability to take a city that had never been challenged before, and the walls came down!
When David faced Goliath, he knew who his God was. He had already confronted a lion with that same authority, and the Bible says he tore open the mouth of the beast. When David spoke, it was with the sound of heaven.
These stories above had one common denominator.