James 1:18

Of His own will He brought us forth by the word of truth, that we should be a kind of firstfruits of His creatures.

His good will and pleasing desire brought us forth into a new birth: like His Son, we are born from a prophetic word of truth. We come forth from Truth Himself, therefore lies and deception are contrary to our nature. 

We should chafe at lies and falsehood, for these are unnatural to the nature of truth from which God brought us forth. As we awaken to the revelation that our natures hail from truth, believing the enemy's lies should be as unnatural to us as our telling a lie. We come from Truth, truthfulness is akin to our new natures, and believing the Truth Himself is natural to us.