Biblical Reference:
The phrase "Peace I leave with you" is found in the Gospel of John, specifically in John 14:27. In the Berean Standard Bible , the verse reads: "Peace I leave with you; My peace I give to you. I do not give to you as the world gives. Do not let your hearts be troubled; do not be afraid."

Context and Background:
This statement is part of Jesus' farewell discourse to His disciples, which spans John chapters 14 through 17. These chapters are set during the Last Supper, just before Jesus' arrest and crucifixion. Jesus is preparing His disciples for His imminent departure and the coming of the Holy Spirit. The promise of peace is a significant aspect of His reassurance to them.

Theological Significance:
1. Divine Peace: The peace that Jesus refers to is not merely the absence of conflict or turmoil. It is a profound, divine peace that stems from a right relationship with God. This peace is rooted in the Hebrew concept of "shalom," which encompasses completeness, welfare, and harmony.

2. Contrast with Worldly Peace: Jesus makes a clear distinction between the peace He offers and the peace the world provides. Worldly peace is often temporary and dependent on external circumstances. In contrast, the peace of Christ is enduring and internal, unaffected by worldly troubles.

3. Role of the Holy Spirit: The peace Jesus promises is closely linked to the coming of the Holy Spirit, the Comforter, who will dwell within believers. The Holy Spirit empowers Christians to experience and maintain this peace, even amidst trials and tribulations.

4. Encouragement Against Fear: Jesus' exhortation to not let their hearts be troubled or afraid is a call to trust in His sovereignty and provision. This peace is a safeguard against fear and anxiety, offering believers confidence in God's ultimate plan and purpose.

Practical Implications for Believers:
1. Trust in Christ: Believers are encouraged to place their trust in Jesus, who is the source of true peace. This trust is cultivated through prayer, meditation on Scripture, and reliance on the Holy Spirit.

2. Witness to the World: The peace of Christ serves as a powerful testimony to the world. In a world filled with unrest and uncertainty, Christians are called to be ambassadors of this peace, demonstrating the transformative power of the Gospel.

3. Inner Tranquility: The peace Jesus offers provides inner tranquility that transcends understanding (Philippians 4:7). It enables believers to remain steadfast and hopeful, regardless of life's challenges.

4. Community Harmony: Within the body of Christ, this peace fosters unity and reconciliation. Believers are urged to "make every effort to keep the unity of the Spirit through the bond of peace" (Ephesians 4:3).

Historical and Cultural Insights:
In the first-century Jewish context, peace was a highly valued concept, often associated with the Messianic hope of restoration and prosperity. Jesus' promise of peace would have resonated deeply with His disciples, who were familiar with the turmoil of Roman occupation and the longing for deliverance.

Conclusion:
The promise "Peace I leave with you" remains a cornerstone of Christian faith, offering assurance and hope to believers throughout the ages. It is a reminder of the enduring presence and power of Christ in the lives of His followers.