First, there are those who operate from a Correspondence theory of truth. Simply put, this means that for a statement to be true it must correspond with reality. Most of us assume that when we speak to others they are operating from a correspondence theory of truth. However, such is not the case. This seems to be the case with Dr. Hamm.
Truth becomes relative, and is very much dependent upon the situation.
The deceit part enters in when Rev. Jones does not bother to explain to you how he understands truth. He may verbalize a faith that sounds like yours. You need to find out first how that person views truth. Many, like Dr. Hamm, are convinced that we cannot have absolute knowledge about God. Scripture cannot be a revelation from God if we lack certain knowledge of God.