The people who read the shirt know what it means to them.
To you it means blasphemy. To them it means salvation. But hey, they are saved or damned already so it doesn't matter.
You can argue all day.... but the bottom line is that if you want to print something about God on your shirt, or your car, or carry a sign in public... it does matter how the public preceives it. It does matter what you say about God. And I can't believe you would think otherwise.