The covenant was an agreement that God initiated with humanity. Some Covenants have conditions while others do not. Covenants between God and man, however, differed from purely human covenants, in that they were not agreements between equals.
God was always the giver and man the receiver. For example, God's covenant with Adam before the fall required obedience to His commands, with the prospect of either life or death. The covenant with Abraham contained no conditions, but only promises of blessing to him and his descendants. These promises pertain to us as well, since those who love the Lord are children of Abraham through faith in Christ.
Jeremiah 31:31-34, provides an encouraging conclusion to the saga of Israel and Judah once they have repented and returned to the land. It shows that this is the same covenant that the church has already made with God. Rather than doing away with the law of God, the New Covenant gives the people the means, not merely to obey it, but to accept it and make it a part of their lives.
God remains faithful and He re-established the covenant with His people. Now, this covenant that has been made between God and the Israelites was not a contract in the usual sense because a contract must normally be made between two equals.
Human beings are not able to reach out and establish a bond with God, but God is able to reach out to us. And that is exactly what the old covenant was about.
Jeremiah understood too well that God's people have not been able to keep the old covenant. He realised that a new covenant between God and humanity is needed to give the people of Israel and Judah new hearts so that they will finally be able to follow God consistently and have real relationships with Him.
In John 15: 1-8, Just as Jesus is intimately related to the Father, so the branches can do nothing unless they abide in relationship with their resurrected Lord, We as Christians need to be attached to receive the sap that enables us to make a difference in the world.
The word “remaining" suggests something continuous, not a one-off event or action. Jesus, therefore calls us to "remain" in Him. That way, He can nurture us. Remaining in Him involve staying closely connected to Him, though all the classic ways: prayer, Bible reading, worship, the sacraments, fellowship, etc.
We have to demonstrate that remaining in Christ's love, is by obeying. Obedience is the cardinal requirement for all believers. Many people try to be good, honest people who do what is right. But Jesus says that the only way to live a truly good life is to stay close to Him, like a branch attached to the vine.