In Romans 4 Paul uses Abraham as an example of faith and how in Genesis 15 God promised him a son and from that son descendants as many as the stars. It says that “Abraham believed God and it was accounted unto him for righteousness”. But Romans 4:20-21 goes further and says, “He did not waver at the promise of God through unbelief, but was strengthened in faith, giving glory to God, and being fully convinced that what He had promised He was also able to perform.”
“He did not waver” – his faith did not fail, he was not unbelieving in God’s promise. The result was that his faith was strengthened and he glorified God.
“He was fully convinced” – this is not just assent; it’s not a mere believing, he was “fully convinced”. He was certain and sure without any doubt. One synonym is “converted”. His mind was changed, he was won over and convinced. He was completely confident that what God promised He was also capable to perform and would perform it – no matter the obstacles. This, according to Romans 4, is saving faith.
In Gen 21 it says, “And the LORD visited Sarah as He had said, and the LORD did for Sarah as He had spoken. For Sarah conceived and bore Abraham a son in his old age, at the set time of which God had spoken to him.” (Vs. 1-2) The promised son had come, God had been faithful. But that’s not the end of the story. It was a number of years later when God spoke to Abraham again. In Gen. 22:1 we read, “Now it came to pass after these things that God tested Abraham, and said, ‘Abraham!’ And he said, ‘Here I am.’ Then He said, ‘Take now your son, your only son, Isaac, whom you love, and go to the land of Moriah and offer him there as a burnt offering on one of the mountains of which I shall tell you’. So Abraham rose early in the morning and saddled his donkey, and took two of his young men with him, and Isaac his son; and he split the wood for the burnt offering, and arose and went to the place of which God had told him.” (Gen 22:2-3)
Abraham, no doubt, did not understand this command given by God, but he obeyed nonetheless. “And Abraham said to his young men, ‘Stay here with the donkey; the lad and I will go yonder and worship, and we will come back to you.’” (Gen 22:5) Abraham said “we will come back to you”. Abraham believed that God would keep His promise that Isaac was the promised heir and seed. Isaac would not be lost. He went on in faith.
“So Abraham took the wood of the burnt offering and laid it on Isaac his son; and he took the fire in his hand, and a knife, and the two of them went together. But Isaac spoke to Abraham his father and said, ‘My father!’ And he said, ‘Here I am, my son.’ Then he said, ‘Look, the fire and the wood, but where is the lamb for a burnt offering?’ And Abraham said, ‘My son, God will provide for Himself the lamb for a burnt offering’.” (Gen 22:6-8)
Abraham was obedient to the fullest and as he was about to slay his son the Angel of the Lord spoke to him, "’Do not lay your hand on the lad, or do anything to him; for now I know that you fear God, since you have not withheld your son, your only son, from Me.’ Then Abraham lifted his eyes and looked, and there behind him was a ram caught in a thicket by its horns. So Abraham went and took the ram, and offered it up for a burnt offering instead of his son.” (Gen 22:12-13)
This is one of the most beautiful shadows of the substitutionary death of Christ in the Old Testament. Hebrews 11:17-19 says, “By faith Abraham, when he was tested, offered up Isaac, and he who had received the promises offered up his only begotten son, of whom it was said, ‘In Isaac your seed shall be called,’ concluding that God was able to raise him up, even from the dead, from which he also received him in a figurative sense.”
Abraham believed God. He did not waver. He was completely confident in God’s ability to not only fulfill His promise but to keep it to the end. He reasoned that God would even raise Isaac up from the dead if needed and he obeyed God’s command in faith all the way to the end.
There is a saying that says “Faith is not believing that God can, but knowing that He will.” There is truth in that statement. Anyone can assent to God’s power and ability to do things, but to know that He actually will do it is another matter. How deep is our faith? Do we really believe that God will do what He has promised? That He will answer our prayers (provided of course they are according to His will)?
Shortly before his death Paul wrote, “for I know whom I have believed and am persuaded that He is able to keep what I have committed to Him until that Day.” (2 Timothy 1:12) Like Paul and Abraham we can completely trust our God. He keeps His promises even when it looks impossible and is ever faithful to fulfill His Word. Let us trust Him fully.