Abraham was the father of the Jews but he is also known as the father of all those who have become children of God through faith in Jesus Christ (Ro.4:16). There are others who walked by faith in God, but Abraham stands out as one who remained in faith against all odds. When God promised him and Sarah a son he was 75 years old, already old and beyond the age of childbearing. But he believed what God promised because it was God who had said it, and that faith was what was counted to him as 'righteousness' (v.3). But then, Abraham and Sarah didn't receive the promised son for another 25 years! Even though they had some doubts now and then, on the whole Abraham held on to God's promise. We can imagine how things went every year as they got older and the chances of their ever having a child plummeted down! But the wonderful thing was that they didn't believe what nature and common sense told them when they pitted such notions against what God had said, but they held on to God's word (vv.19-21). That was a remarkable faith! No wonder Abraham received the title of the father of faith!
We too are to walk in faith in the paths of our own lives even though our circumstances may be different from Abraham's. But we too may have our tests of faith that look just as difficult! The example of Abraham is given to us so that we too may learn to persevere without giving up.
We must be sure that we are holding on to something God has promised us and not doggedly holding on to something we want for ourselves. We mustn't even say that what God did for someone else He has to do for us, unless it is something He has promised for everyone, because God does many things for individuals as special cases. Faith is not something we create in our own mind but which is based on God's word of promise which He has spoken to us (10:17).
But once we are clear that what we believe is something God has promised all His children or something He has told us specifically, we can dare to think that God will definitely fulfil it. If we don't believe that, it would be unbelief which is certainly displeasing to God. Remember, all of Israel except two people who believed perished in the desert and could not enter the Promised Land!
Jesus came to save His people from their sins (Mt.1:21). He came to set captives free (Lk.4:18). Because of His death on the cross in our place He has done everything needed for our salvation from sin (He.7:27;Jn.19:30). As a result, we are no longer obliged to serve sin (Ro.8:12). Sin need not rule over us any more (6:14). This is a promise given to every child of God.
The question is if we will believe it. It is a choice we make whether we will believe what God has said or believe our circumstances. Our situation may be less severe or even worse than Abraham's. But our trust is not in us or our abilities but in God who has promised things to us. If we hold on in faith, we too can see the fruit just like Abraham.