There was no hope that Abraham would have children, but Abraham believed God and continued to hope. And that is why he became the father of many nations. As God told him, “You will have many descendants.” Abraham was almost a hundred years old, so he was past the age for having children. Also, Sarah could not have children. Abraham was well aware of this, but his faith in God never became weak. He never doubted that God would do what he promised. He never stopped believing. In fact, he grew stronger in his faith and just praised God. Abraham felt sure that God was able to do what he promised. So that’s why “he was accepted as one who is right with God.” These words (“he was accepted”) were written not only for Abraham. They were also written for us. God will also accept us because we believe. We believe in the one who raised Jesus our Lord from death. Jesus was handed over to die for our sins, and he was raised from death to make us right with God.
Romans 4:18-25 (ERV)
When God promised Abraham that he would be the father of all nations, He was declaring His desire that He alone would fulfil everything He had stated. But it was up to Abraham to believe and steward that promise until it was fulfilled. Abraham leaned his life towards agreeing with God, and his faith was considered righteousness. It was the receptivity of his heart to God’s promise that enabled him to obey even though it was incredibly difficult.
Bear in mind, it was God Himself who wanted to make Abraham great, not Abraham’s prayers. If his prayers bring about God's intended purpose, they become works based on his human efforts rather than God's incredible acts of grace. In other words, God did not answer Abraham's prayers because he was faithful; rather, God answered Abraham because He is faithful to the promise He has made. All Abraham had to do was to believe and fully rest on the word of God.
Likewise, when we pray, we pray with the revelation of what Christ has done for us in His finished work. Hence, it is not how hard we pray but how much we believe and lay hold on what is ours in Christ. There are no more “If it is your will” kind of prayers when we know all the promises of God find their “Yes” in Christ and that is why we say “Amen” through Christ to the glory of God (1 Corinthians 1:20)
Pray according to who you are and what you have in Christ, not how you feel or think.
The Spirit of Christ who dwells in us helps us pray and intercede for us (Romans 8:26-27). We don't need to qualify ourselves in order for God to hear us since Christ has already qualified us before the Father. This truth frees us to pray without ceasing and to be steadfast without fear.