When to use que and when not to

Question

Whats the difference between saying something like " que dios te bendiga " and " dios te bendiga "

Answer 1

The first can be a wish or a hope. The second looks like a statement and should probably read "dios te bendice".

Answer 2

Just to mention it:

In a previous thread it was pointed out that many of these exhortations are "clipped" sentences.

[Espero ] que dios te bendigas.

which is why the subjunctive is required. Remove the que and we are no longer in a subordinate clause where we normally use the subjunctive. (as Eddy points out).