God himself answers the question if his word is always true, in the book of Exodus !                                                        

* Background Context: (In this chapter of Exodus, Moses asks God if he would let him see his full glory.  God granted Moses this very unique and singular honor to see his glory up close.  No other human being has been granted this kind of personal, one-on-one encounter with God.) 

 

(God Proclaims Himself to Moses)

Exodus Chapter 34, Verse 6 and 7: 

Then the Lord passed by in front of him and proclaimed, “The Lord, the Lord God, compassionate and gracious, slow to anger, and abounding in lovingkindness and truth;

   

who keeps lovingkindness for thousands, who forgives iniquity, transgression and sin; yet He will by no means leave the guilty unpunished, visiting the iniquity of fathers on the children and on the grandchildren to the third and fourth generations.”