In the time of Noah, God "saw that the wickedness of man was great in the earth, and that every intention of the thoughts of his heart was only evil continually" (Gen. 6:5). Humanity has a heart problem. The heart is the center of human longing. It is the center of human existence. And it is, according to Jesus, "out of the heart" that "come evil thoughts, murder, adultery, sexual immorality, theft, false witness, slander" (Matt. 15:19). Nothing good can come from the hidden depths of our rotting, wicked hearts. As Paul says in Romans 8:6, "the mind" set "on the flesh is death." Humanity in its lostness and depravity participates in a living death, a life lived teetering on the precipice of eternal death and damnation. This is a life that cannot even be called life, even though blood is coursing through one's veins and one's heart is still beating.
The desperate disease of the sin-infected human heart requires radical surgery. What sinners need, in fact, is a transplant. A new heart is the only solution. The Apostle Peter begins his first letter with a glorious picture of the way in which God has met sinful humanity in its most fundamental need: "Blessed be the God and Father of our Lord Jesus Christ! According to his great mercy, he has caused us to be born again to a living hope through the resurrection of Jesus Christ from the dead" (1 Peter 1:3). Peter packs an enormous amount of theology and doxology into this verse. God is to be praised because He has given believers the heart transplant they so desperately needed, although He was under no compulsion to do anything good for rebellious sinners. He works in their hearts solely because of His "great mercy." While we were once dead in our trespasses and sins (Eph. 2:1), God has caused us to be reborn spiritually. Help from God is not enough; our old selves must die and undergo a spiritual resurrection. Only then will our hearts be truly alive.
The new life, the "living hope," that we have entered into is said by Peter to have come to us "through the resurrection of Jesus Christ from the dead" (1 Peter 1:3). This is true in two ways. First, believers are said in the New Testament to have died with Christ and to have been raised up to newness of life with Him (Rom. 6:3–4). This means that the very power that was at work to raise Jesus from the dead is at work in the heart of the believer, and it has been since the very moment of the believer's miraculous rebirth. This is the foundation for all spiritual growth in the Christian life. Second, in His death, Jesus entered into the new creation as the "firstfruits" of all believers (1 Cor. 15:23). In the Old Testament, the festival of the firstfruits occurred when the crops first started to yield produce. At that time, the Israelites would gather a small amount of this initial fruit to offer to God in anticipation of the full harvest to come later. In the same way, Jesus Christ as raised from the dead is the first-fruits of believers: because He has already entered into the new creation, we know for certain that we will also join Him there, and that in a very important sense, we are already living in the new creation (2 Cor. 5:17). There is an unbreakable connection between what is already true of Jesus and what is true of us now and at His return. This should give great confidence to God's people, who have the Holy Spirit living within them as the guarantee of their future, full possession of the riches of heaven (2 Cor. 1:22; 5:5; Eph. 1:14).
The new life of the resurrected Jesus flows into the hearts of believers, so "living hope" is at the heart of what it means to be a Christian. The nightmare of living death, with eternal death looming over the horizon, is but a distant, fading memory. A living hope is a hope that gives life, a hope that blooms and blossoms within our hearts. Hope, for the believer, is certain knowledge of the destiny that awaits us after death. It is not the weak substitute for hope that we hear all around us: "I hope it doesn't rain today." "I hope I get a promotion at work." It is hope founded on the "inheritance that is imperishable, undefiled, and unfading, kept in heaven for you" (1 Peter 1:4). The riches of full and final salvation in heaven are secure for all of God's children. We haven't yet received the fullness of this inheritance, but even now "by God's power" we "are being guarded through faith for a salvation ready to be revealed in the last time" (1:5). Christian "faith is the assurance of things hoped for, the conviction of things not seen" (Heb. 11:1). Hope is living because it gives life to weary sinners in the midst of their struggles.
Because of this unshakable confidence in the salvation God has worked for us in Christ and will continue to work for us until the last day, the Christian life should be characterized by rejoicing, even in the midst of intense difficulties and trials (1 Peter 1:5–7). How can our hearts not overflow with joy and thankfulness to our great God? And with joy in our hearts, we must prepare our "minds for action" and be "sober-minded." That is to say, we must think rightly about who we are in Christ and as a consequence "set [our] hope fully on the grace that will be brought" to us when Jesus returns. Our hope is secure: no matter what tragedies and hardships we face in this life, Jesus will come back to rescue us in the end.