whenever our heart convicts us [in guilt]; for God is greater than our heart and He knows all things [nothing is hidden from Him because we are in His hands].

If we claim to have no sinful practices [in our lives], we are self-deceived and are not being truthful about the matter.

He that believes on the Son of God has the testimony in him self: he that believes not God, has made him a liar, because he has not believed the testimony which God has borne concerning his Son.