Why is the concept of Christ's voluntary suffering important for Christians?

In John 18, Christ's arrest and subsequent suffering demonstrate His willingness to endure suffering for the sake of sinners. Despite having the power to avoid His fate, He chose to submit to the will of God, showcasing a love that surpasses human understanding. This act of voluntary suffering is central to the doctrine of substitutionary atonement, wherein Christ suffers for the sins of humanity, as stated in 1 Peter 3:18. For Christians, this is foundational, as it defines the nature of Christ's sacrifice and highlights the depth of His love and compassion for a sinful world, fulfilling the prophecy and purpose of salvation.