God is true. His Word of promise is sure. In all His relations with His people God is faithful. He may be safely relied upon. No one ever yet really trusted Him in vain. We find this precious truth expressed almost everywhere in Scriptures, for His people need to know that faithfulness is an essential part of the divine character. This is the basis of our confidence in Him. But it is one thing to accept the faithfulness of God as a divine truth, it is quite another to act upon it. God has given us many “exceeding great and precious promises,” but are we really counting on His fulfillment of them? Are we actually expecting Him to do for us all that He has said? Are we resting with implicit assurance on these words, “He is faithful that promised” (Hebrews 10:23).
Pink, Arthur W.; The Attributes of God; Kindle Edition; page 51