Romans 4:18-25 (New International Version)
18Against all hope, Abraham in hope believed and so became the father of many nations, just as it had been said to him, "So shall your offspring be."[d] 19Without weakening in his faith, he faced the fact that his body was as good as dead—since he was about a hundred years old—and that Sarah's womb was also dead. 20Yet he did not waver through unbelief regarding the promise of God, but was strengthened in his faith and gave glory to God, 21being fully persuaded that God had power to do what he had promised. 22This is why "it was credited to him as righteousness." 23The words "it was credited to him" were written not for him alone, 24but also for us, to whom God will credit righteousness—for us who believe in him who raised Jesus our Lord from the dead. 25He was delivered over to death for our sins and was raised to life for our justification.
There are a lot of promises that we can find in the Bible. In fact I think all of it are promises and truths that we can claim. Here are some of them:
We are troubled on every side, yet not distressed; we are perplexed, but not in despair; Persecuted, but not forsaken; cast down, but not destroyed; 2 Corinthians 4:8, 9
And we know that all things work together for good to them that love God, to them who the are called according to His purpose. Romans 8:28
Casting all your care upon him; for he careth for you. 1 Peter 5: 7
The young lions do lack, and suffer hunger: but they that seek the Lord shall not want any good thing. Psalm 34:10
Can a woman forget her sucking child, that she should not have compassion on the son of her womb? Yea, they may forget, yet will I not forget thee. Behold, I have graven thee upon the palms of my hands; thy walls are continually before me. Isaiah 49:15,16
Now those are really great promises. Promises that we can really hold onto and believe in.
But I think that's not the main issue. The issue is "Are we Persuaded that God can do and will do what He had Promised?" These promises will remain futile and empty unless we choose to believe in them.
Abraham believed in God even how illogical and unrealistic the promises were that's why in the end "it was credited to him as righteousness".
SO why don't you review all the promises you have read and heard before and start to believe and have faith in God and be persuaded that GOD CAN!
God Bless you!