God has entered into covenant with man. In the Old Testament God laid out the terms of the covenant both the stipulations and the benefits. You need to understand that these terms are “the way it is.” Therefore if we learn to trust and obey God, it will be well with us and if we don't, it won't be well with us. (Deut. 30:19-20, Jer. 7:23, Matt. 10:7-14, Mark 11:23-24,Luke 1:71-75,Luke 19:42, II Cor.1:20)
In the old covenant the blessings were obtained by trying to be good, trying to obey God, and trying to trust God. When God’s people missed it, there were procedures to go through so that they could receive forgiveness and continue in their covenant relationship. But in the new covenant God gives us His Spirit so that we can do His will. (John 20:21-23, Acts 2:38, Romans 8:2-17, Hebrews 8:10-11)
It works like this: Jesus, the second Adam, took the kingdom back from Satan who had weaseled it away from Adam. He took it back by doing right everything that Adam had done wrong. He denied the flesh and walked by the spirit. He hearkened unto God and not the liar. He shed His own innocent blood to atone for the first Adam's bad choice which had started the shedding of innocent blood in the earth. This kingdom belongs to Jesus and he had forever placed it in the hands of spirit-filled men and women. (Read Matt., Mark., Luke, John, Romans 3:10-18,5:8,14-21,6:23, I Corinth. 15:21-50, II Corinth. 5:21)
Jesus also, before paying the price and defeating the devil, fulfilled man's part of the old covenant which was to obey God and walk in His ways. Since Jesus fulfilled the covenant, it stands as a sealed agreement forever. All God promised to man belongs to Jesus. The covenant is between Jesus and the heavenly Father and it is sure to Him and all those who abide in Him.
The new covenant is that God will fully equip the believer to walk in covenant with Him as Jesus did. God has provided the believer with His Spirit and has given them Jesus to be their example, fore-runner, captain, shepherd, savior, high priest, big brother (study Jewish custom there), and the author and finisher of their faith. He is the Way, the Truth, the Life, the Bread, the light and the true Vine for believers. God has also provided believers with the full armor of God (study Eph. 6), the written Word, and the great and precious promises. Not only that but the believer is reconciled to God as His child and this covenant is literally a Father/child relationship written out and sealed by the blood of the lamb. (Romans 5:10-11, 8:14, Ga1. 4:5, I Peter 1:21-25)
God has provided believers with all good things including the equipment to overcome. (Is. 53, 54, II Peter 1:3) He promises to be their Father and love them, never leave them, and give them a spirit that cries, "abba Father" or in other words, a spirit that know a kinship to God and delights in pleasing Him. God guides, leads, and teaches believers by His Spirit--the Spirit of Truth (John 16:7-15) who is always with the believer to help him/her combat the liar.
The believer’s part of the covenant is to trust and obey. God’s part is to be a Father to him/her. The believer abides in Christ by trusting and obeying--being a doer of the Word and not a hearer only. (James 1)
II Corinthians 1:20 boldly states that all promises are ‘yes’ in Jesus because the covenant between God and Jesus is sure and if the believer abides in Jesus, it is sure for him/her. The covenant is not based upon the believer’s merits--thus the promises are sure--they can only be null and voided by the believer’s choice to abide in the world instead of in Jesus. They may not all manifest if the believer does not walk by faith. The believer can still mess up, but he/she doesn’t have to. He/she may remain spiritually poor, ignorant, and/or sick, but he/she doesn’t have to because he/she is in covenant with God and He has laid out the terms of the agreement in The Holy Bible.