The faithfulness of God is our comfort, strength, protection, and foundational to our trust in Him. He does not fail. God never breaks a promise, and He never leaves us on our own (Deuteronomy 31:6). If God were not faithful, there would be no reason to follow Him. Every person in life will eventually let you down. Every source of security in this life will fail.
Money can be lost as quickly as it was gained. Security can be shattered in an instant. People and circumstances change, but God never does. He is the same yesterday, today, and forever (Hebrews 13:8). The faithfulness of God will sustain you through your darkest hours and cause you to experience overflowing joy when you are walking in His ways.