The life of faith we are called to follow has no immediate tangible rewards. Put simply, faith believes a promise of eternal life and peace with God. A better word than promise is 'covenant' – a binding promise in which there is blessing for keeping the promise and a curse for those who do not. But how do we know the covenant-promise will be fulfilled? In part, we rely on what we know of the character of the person making the promise, and in part we want to know how the promise will be guaranteed. That is where vows and oaths come in.

There are two kinds of promise: a vow, in which somebody promises God that he or she will do something; and an oath in which a person makes a promise to another but asks God to be a witness and to guarantee that the promise will be kept. These covenant-promises had a statement of the blessing which comes from fulfilment, and cursing which comes from non-fulfilment.

But what if God makes a promise? Who is His witness, who will guarantee His words? Clearly it cannot be somebody with less power or authority. When God made His covenant with Abraham (Genesis 22:15-18) after he had been willing to sacrifice his son Isaac (but God provided a substitute sacrifice), He confirmed His previous promise (Genesis 12:2-3) and swore an oath that He would fulfil what He had said. Why is this important? There is nobody greater than God and so God chose to swear by His own Name. It gave Abraham confidence to travel onward in faith, even though he died without seeing its fulfilment (Hebrews 11:39-40).

Alas, whatever oaths or vows we make, in some way we break them all. So it is wonderful that Jesus has become the substitute sacrifice for us, taking our curse. God never breaks any promise: He does not need a sacrifice to Himself for His sin, but He has sent Jesus to be cursed instead of us. That is why we can continue in faith – however faulty our promise-keeping, we have a sacrifice for sins which gives us confidence to get up and walk on again with Jesus. And because He never fails, we can trust Him to be our advocate in heaven, our shepherd and counsellor, our priest and king. So, we can trust God's promises and have the confidence to keep on until we see Jesus, knowing that all our failures have already been met by His sacrifice (Hebrews 10:35).