Faith is an unshakable belief in God and the promises of God. Faith also involves God’s commands. We’re expected to put such confidence in everything God tells us to do that we actually do it!
So how do we dishonor God by a lack of faith? When we disbelieve God, we are in essence saying to God, “I don’t really believe You’ll do exactly what You say you will do. And I don’t really believe that You are what You say You are.”
And God’s response to that is, “I am a promise-keeping God!”
So a lack of faith insults God. God has never failed once—He’s always kept the promises He’s made to human beings. And He always will! (Provided, of course, that we meet the conditions He outlines.)
Faith is one of the key qualities God is looking for in us, so it only makes sense that we make sure we have it.