“God is faithful, by whom ye were called unto the fellowship of his Son Jesus Christ our Lord.” 1 Corinthians 1:9
Another moral attribute of God is God’s faithfulness. What does it mean? When you say that God is faithful, you mean that He is one upon whom you can safely lean. It means one on whom you can absolutely rely, one upon whom you can depend, one upon whom you can secure yourself, without ever being in doubt that He will suddenly let you go.
The Bible has some glorious statements about this. It tells us about the faithfulness of God who always keeps His promises and never breaks His covenants. It tells us that God will always fulfil every word that has ever gone out of His mouth (Isaiah 55:11). It tell us that God will always faithfully and certainly defend and deliver His servants at all times of trial, testing , and conflict. It tells us that God can be relied upon to confirm and to establish all whom He has called, guarding them from the evil one and keeping them and guiding them until His purposes are fulfilled in them.
Listen to one great statement of all that: “God is faithful, by whom ye were called unto the fellowship of his Son Jesus Christ our Lord” (1 Corinthians 1:9). Whatever else may happen, whatever may be going wrong, Paul tells those people to be sure of this- God is faithful. Again he says, “And the very God of peace sanctify you wholly; and I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ” (1 Thessalonians 5:23). Then notice, “Faithful is he that called you, who also will do it” (v. 24). This is absolutely certain: Nothing can frustrate Hi plans; nothing can make Him forego what He has promised; nothing can cause Him to change what He has purposed with respect to you. – Dr. Marytn Lloyd-Jones