On one hand, choosing the greatest promises in the Bible is completely subjective. The “greatest promise” of God in the Bible for any particular person is going to depend on the needs and feelings of that individual at a given moment. But the promises listed below are among those that would probably be high on the list for most people:
John 3:16: “For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.”
Proverbs 3:5–6 “Trust in the Lord with all your heart and lean not on your own understanding; in all your ways submit to him, and he will make your paths straight.”
Hebrews 13:5 “Never will I leave you; never will I forsake you.”
Matthew 6:25–33 “Therefore I tell you, do not worry about your life, what you will eat or drink; or about your body, what you will wear. Is not life more than food, and the body more than clothes? Look at the birds of the air; they do not sow or reap or store away in barns, and yet your heavenly Father feeds them. Are you not much more valuable than they? Can any one of you by worrying add a single hour to your life? And why do you worry about clothes? See how the flowers of the field grow. They do not labor or spin. Yet I tell you that not even Solomon in all his splendor was dressed like one of these. If that is how God clothes the grass of the field, which is here today and tomorrow is thrown into the fire, will he not much more clothe you—you of little faith? So do not worry, saying, ‘What shall we eat?’ or ‘What shall we drink?’ or ‘What shall we wear?’ For the pagans run after all these things, and your heavenly Father knows that you need them. But seek first his kingdom and his righteousness, and all these things will be given to you as well.”
Isaiah 40:29–31 “He gives strength to the weary and increases the power of the weak. Even youths grow tired and weary, and young men stumble and fall; but those who hope in the Lord will renew their strength. They will soar on wings like eagles; they will run and not grow weary, they will walk and not be faint.”
Jeremiah 29:11 “‘For I know the plans I have for you,’ declares the Lord, ‘plans to prosper you and not to harm you, plans to give you hope and a future.’”
Philippians 4:6–7 “Do not be anxious about anything, but in every situation, by prayer and petition, with thanksgiving, present your requests to God. And the peace of God, which transcends all understanding, will guard your hearts and your minds in Christ Jesus.”
Psalm 23 “The Lord is my shepherd, I lack nothing. He makes me lie down in green pastures, he leads me beside quiet waters, he refreshes my soul. He guides me along the right paths for his name’s sake. Even though I walk through the darkest valley, I will fear no evil, for you are with me; your rod and your staff, they comfort me. You prepare a table before me in the presence of my enemies. You anoint my head with oil; my cup overflows. Surely your goodness and love will follow me all the days of my life, and I will dwell in the house of the Lord forever.”
Mark 11:24 “Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours.”
Philippians 4:13 “I can do all this through him who gives me strength.”
Philippians 4:19 “And my God will meet all your needs according to the riches of his glory in Christ Jesus.”
Sometimes the promises in the Bible are taken out of context, and people end up thinking the Bible says something it doesn’t really say. For instance, does the Bible teach that we can have everything we want in prayer? No, John 14:13–14 must be kept in context. Does God promise every individual alive a “hope and a future”? No, Jeremiah 29:11 must be kept in context.
Some of God’s promises in the Bible have great scope and impact. The first promise that God gave Adam and Eve was very great indeed: “You are free to eat from any tree in the garden; but you must not eat from the tree of the knowledge of good and evil, for when you eat from it you will certainly die” (Genesis 2:16–17). This promise Satan flatly denied, and in unbelief Adam and Eve ate from the fruit, and sin and death entered the world. All of us, being descended from Adam and Eve ratify their decision to disobey God, and so that promise applies to us as well (Romans 5:12). This is probably the most terrible promise in the Bible, and it is the greatest in scope—it applies to literally everyone.
However, God did not leave humanity under condemnation with no way out. He entered the human race as a man (Jesus Christ), lived a perfect life, and died, taking the death we deserved. He then rose again. When a person is united with Christ in faith, another promise applies. This promise is repeated over and over in places such as Romans 8:1–4: “Therefore, there is now no condemnation for those who are in Christ Jesus, because through Christ Jesus the law of the Spirit who gives life has set you free from the law of sin and death. For what the law was powerless to do because it was weakened by the flesh, God did by sending his own Son in the likeness of sinful flesh to be a sin offering. And so he condemned sin in the flesh, in order that the righteous requirement of the law might be fully met in us, who do not live according to the flesh but according to the Spirit.”
By any measure, the promise of salvation by grace through faith is the greatest promise in the Bible. Once a person becomes a child of God by faith, then the other promises find their proper context. Many of the promises that are often pulled out of context really only apply to the child of God. The person who is not in Christ is still under the deadly promise of punishment, and that is the promise that such a person should hear and understand. It is misleading for a Christian to apply the promises of God to one who is not in Christ.
The two greatest promises are summed up in Romans 6:23: “For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord.”