When God speaks, does He need to affirm what He promises by an oath? The simple answer is, "No". God does not need to put Himself under oath for somebody else to hold Him to account. He is God and whatever He says has ultimate authority. But throughout the Bible, many people have needed reassurance that what they have heard has really come from God (Matthew 14:28). Therefore, the Lord gave signs or additional words confirming what He had said, encouraging His people that they had heard correctly, so it was safe for them to step forwards in faith.

Abraham also received words and signs from God. Most of the signs followed his faith rather than preceded it (including Isaac's birth when Abraham was 100 years old). God's first promise, to make a great nation from Abraham's descendants, was in Genesis 12:1-3 when Abraham was 75 years old. That promise was expanded in Genesis 15:1-21, when Abraham was 85 years old, to include foreknowledge of slavery in Egypt and entry into the Promised Land: it was accompanied by a sign (Genesis 15:17). Further promises came regarding circumcision, the Land, Ishmael, Sarah and Isaac; until Isaac was bound on the altar of sacrifice (Genesis 22:1-14) when Abraham was around 125 years old.

At that point God again promised Abraham that his faith will be the template for God's blessing (Genesis 22:15-18). Unusually, God confirmed His promise with an oath. There is nobody greater than God, so He staked His whole existence on keeping His promise. Put in another way, if He could not deliver His promise then He could not be God. That oath was also important for subsequent generations, encouraging them to keep trusting God (Exodus 13:11; 32:13; 33:1). The repeated accusations by Israel's enemies that their God was weak was countered by their confidence in His oath. Every sign of its fulfilment was a potent reminder that God is God, and is fully trustworthy (Judges 2:1). Abraham knew how to wait in faith, because he was confident that God would keep His promises, however long that might take.

God's promised blessing is not restricted to Israelites. It is for all who are made righteous because they trust God's Word (Romans 3:22). Often we also have to wait. The life of faith is about trusting although we cannot see, and believing God will fulfil His promises in our time and in the generations to come. We have run away from worthless promises to the only promise-keeping God. Alas our instant-communication age does not like waiting; but wait we must while we allow faith to do its work in us, and through us, for His glory (James 1:2-4). Our God reigns! (Revelation 19:6). So don’t panic, pray with confidence, and wait for the Lord to show His powerful hand (2 Chronicles 20:6; Psalm 123:2).