Unbelief sees only what is visible, but faith sees more. Faith sees God in it, faith remembers and reasons, and then faith acts. At some point in our faith, we must step forward and act—boldly claiming the promises of God reserved for those in Christ.
Death came as punishment for sin. But for the Christian, we are declared righteous in Christ, so death is no longer a punishment. Instead, we have the great hope of eternal life, with glorified bodies, in the presence of Jesus our Lord. This far surpasses the joy we taste in this life. In his wisdom, God has bound up death but has not destroyed it, so as Christians we will still taste physical death. But we can do so in faith that God is in complete control, and in hope of a far better life where all of God's promises are made complete.
Paul references the promises of God to Abraham, the ultimate fulfillment of which is the restoration of fellowship with God and the establishment of God's kingdom in the new heavens and new earth. Abraham and his descendants will be heirs of the world. Paul clearly demonstrates that it was not obedience that secured this promise to Abraham, but Abraham's faith in God and God's grace toward Abraham. Works and reward are utterly opposed to faith and promises. Just as with Abraham, we do not inherit God's promises by obedience or lineage, but we inherit God's promises by faith in God. We too will experience restoration of fellowship with God, and will participate in his eternal kingdom!