David Wilkerson emphasizes that God only accepts perfect righteousness, which is essential for salvation and justification. This righteousness, inherited by true believers through faith, is exemplified by Noah, who became an heir not through his actions but through his belief in God's revelation. Wilkerson highlights that Jesus has left us this perfect righteousness as a legacy, making us richer than any earthly treasure. Understanding this inheritance empowers believers to stand firm against any accusations from the enemy, as they are covered by the righteousness of Christ.