Is saying the opposite of what we believe considered hypocrisy? May Allah reward you.

The ruling on informing against what is presumed varies according to the situation. It may be permissible, such as reassuring a sick person who is presumed to be dying, or it may be deceit, such as contradicting what you believe to be true to someone who sought your advice. It could also be hypocrisy that expels one from the faith, such as harboring doubt in belief while outwardly professing it, or a minor hypocrisy, such as making a promise with no intention of fulfilling it.