In John’s gospel, the Lord Jesus spends time with His disciples in an upper room prior to His crucifixion and resurrection. He encourages His disciples and readies them for the battle that lay ahead. In Jn 14:27 Jesus says, “Peace I leave with you, My peace I give to you; not as the world gives do I give to you.” This is a most blessed legacy to leave to His disciples. Matthew Henry commented, “When Christ left the world, He made His will. His soul He bequeathed to His Father and His body to Joseph. His clothes fell to the soldiers. His mother He left to the care of John. But what should He leave to His poor disciples, who had left all for Him? Silver and gold He had none; but He left them what was far better, His peace.” The peace of Christ is a precious commodity that flows from His redemptive work on behalf of His people. Herman Ridderbos wrote, “Jesus’ ‘shalom’ is not a cheap wish. He is now at the point of going away on a journey in which He will have to fight for that peace against the powers of darkness and violence…a peace that He will have to bring back from the depths of death.”
The Apostle Paul writes of the peace of Christ in several places in his epistles. In Eph 2:14-18, he declares that Jesus Christ is our peace (v.14), that He has made peace at the cross (v.16), and that He preached peace to the Ephesians through the apostle’s ministry (v.17). In the book of Colossians, Paul connects the peace of Christ with His reconciling work on the cross, “and by Him to reconcile all things to Himself, by Him, whether things on earth or things in heaven, having made peace through the blood of His cross” (1:20). Gordon H. Clark commented on Col 1:20, “Now, when we pause to consider, this is staggering. The preceding verses have described Christ in transcendent terms. He was the Creator, in whom all the fullness dwells, the heir of the universe, for whom indeed it was created. When now the Creator of heaven and earth, the Creator himself, voluntarily suffered on the cross for our sins, we can only stand in awe and worship.”
In conclusion, it is important to understand that our subjective peace is grounded upon objective truth. Paul writes in Rom 5:1, “Therefore, having been justified by faith, we have peace with God through our Lord Jesus Christ.” The believer knows peace because of what Christ accomplished in His life, death, and resurrection. The believer’s peace is not the outflow of a moral life or of consistent religious observance; rather, the believer’s peace is inseparably connected to the cross of Jesus Christ. The theological truth of justification by faith alone is not simply a concept that differentiates Protestantism from Roman Catholicism; it is the foundation of the believer’s peace with God.
 Herman Ridderbos, The Gospel of John: A Theological Commentary (Grand Rapids: William B. Eerdmans Publishing Company, 1997), 511.
 Gordon H. Clark, Colossians (Jefferson, MD: The Trinity Foundation,  1989), 50.