I think what you're referring to is the idea of deception in the context of fighting against the enemy in battle. Muslims are allowed to use deception then, and i don't know of any other circumstances. If you think i'm lying to you, then that's upto you because i can simply say the same.
I can compare this idea of deception (in the battlefield) to how non muslims are, because combat is done by both sides. And if one is honest to the enemy - then that can bring loss and put the muslims in danger. Therefore it is permissible within them circumstances.
Muslims have high morals compared to any other faith, and these morals were introduced over 1420 years ago, yet these are still more advanced than the immorality we see in todays society.
Justifying things by comparing is done to show the contrast between X and Y, it explains how one is better than the other, and it explains its benefits compared to the others disadvantages.
It's easy to say that a certain religion says so and so, then blaming that party without introducing evidence in the first place. Any sane person will ask you for evidence for your claim, so please try doing that next time insha'Allaah.
Allaah Almighty know's best.
Peace.
