If you hear “Thank God!”, is that an order? Actually, in English, “Thank God!” is a common phrase that people use to express relief over a situation. For example, if your dog ran away from home and you spent the whole day searching for him, only to return and see him waiting for you at the front door, you might exclaim, “Oh, thank God!”
“Thanks God” on the other hand would have to be properly punctuated to, “Thanks, God.” This would be a legitimate form of gratitude expressed toward God. If you aren’t religious, this wouldn’t make much sense to say in conversation, and even then, it’s much more likely to be something someone would say in private during prayer. Of course, you may also hear it said sarcastically. If you’ve had a bad day, you could look up at the ceiling and mutter, “Thanks, God,” to express your overall distaste with the way things are going, as if the universe is out to get you.
To summarize, “Thank God!” is a common expression that you’ll hear people say in person, on TV and in films. It’s a way to express your relief over the closure of a situation you were worried about. “Thanks, God” can be used either sarcastically or personally in prayer, but otherwise isn’t a correct general statement, as most intend. If you ever need to remember which one is correct, just remember the verb tenses. “Thanks” is the third person singular form of the verb “to thank”, and can also be used as a shortened form of “Thank you”. “Thank” is the imperative form of “to thank” and is used to give commands or, in this case, make an exclamation.