Numbers 23:19 (NKJV)
God is not a man, that He should lie, Nor a son of man, that He should repent. Has He said, and will He not do? Or has He spoken, and will He not make it good?
When God makes a promise, you can count on it. Man can and will disappoint you but God is faithful and true. He has promised us many things in his Word: abundant life, heaven, answers to prayer, peace, rest, rich rewards, understanding and wisdom.
Isaiah 40:8 (NKJV)
The grass withers, the flower fades, But the word of our God stands forever."