He didn’t have any moral principles when he signed his last contract, because he hadn’t accepted Jesus yet.
Do you not understand the basic tenants of Christianity? Before accepting Jesus nobody is moral—not a single person (they might thing they are moral, but they are just deluding themselves). They have an immoral nature and live their lives in an immoral manner. That is one of the core beliefs of Christianity.
If indeed he had already joined the church, I would think that he had accepted Jesus when he did so. Isn’t that the idea of it all?