Theism is the belief in God based on revelation.
Deism is the belief in God NOT based on revelation.
Christianity is theism.
If deism is "the belief in God NOT based on revelation," then can someone be an adeist?
Seriously though, none of those definitions are adequate.
1. Many theists do not depend on revelation for their views.
2. Some of the classic arguments for God made by theists were not based on revelation. Example: St. Anselm offered as a logical proof for God, "God is that than which nothing greater can be conceived." Nothing in that statement is based on revelation, so in your definition that would make him a deist. He was certainly not a deist, and not merely a theist, but a full-fledged Christian.
3. And it can't quite be said that Christianity is theism. It's far more than that, and theism certainly is not Christianity -- though many talk as though a Christian is a theist and a theist is a Christian.
Steve.