One of the most vexing questions faced by Christian theologians for nearly two thousand years is that of "grace" versus "works" in the attainment of salvation. The apostle Paul, for example, is often believed to have focused on grace and downplayed the role of works, while the apostle James famously proclaimed that "faith without works is dead" (James 2:26). This book traces the evolution of the idea of salvation from its beginnings in the Old Testament, where the emphasis was on the protection and survival of the nation, through the end of the New Testament, where it came to be understood as the reward of eternal life for each believer. Presenting this development in a systematic way, the authors argue that the apparent contradiction in the biblical teachings on grace versus works is based on a failure to distinguish between the Kingdom of God and eternal life; in brief, the former requires works while the latter is purely the result of grace. This proposal has important implications for the Christian understanding of God's justice and mercy and offers a hopeful message to believers everywhere.