A Spiritual Operation. Colossians 2:11. The sign of circumcision for Jewish males physically confirmed the covenant God made with Israel. The crucifixion and death of Christ have rendered that unnecessary because our commitment to God is now inward, not an outward sign, and is written on the heart of every believer. The evidence of this is the change in the nature and conduct of someone who has experienced spiritual rebirth. The sinful nature has been “crucified with Christ,” and a new nature has been implanted in each child of God by the Holy Spirit when they put their faith in the Lord Jesus Christ.
There are many signs and symbols today that people believe are necessary to demonstrate their Christianity. These include crosses worn as jewelry, fish symbols on bumper stickers, and signs like a hand with fingers pointing to the sky. All of these are outward displays, and I suppose there’s nothing fundamentally wrong with them if people use these things to spread the Gospel. However, God has His own way of working that has been around for a long time. He circumcises the heart of believers so that Jesus Christ becomes Lord. It’s in this inward transformation that the true power of testifying to the Gospel is really seen.
I can place a symbol or sign in a prominent spot on my car, but if I don't live like a Christian, that sign is a mistake. I can wear a pin on my lapel or get a cross tattooed on my arm, but those don't make a true Christian testimony if my words, actions, and teachings are inconsistent with God’s will. “Man looks on the outward appearance, and God looks upon the heart.” I need to remember that what is inside ultimately shows others that a spiritual change has taken place in one's heart. That is where God begins to build and strengthen an authentic testimony that will ultimately reveal the reality of faith and life.
God removes our old nature and replaces it with a new one like His. These two natures are entirely different and incompatible. Maintaining friendship with the world becomes impossible once this spiritual transformation occurs within you. People may observe external things, but the true difference lies in the unseen spiritual qualities that God Himself imparts. As a result, faith becomes genuine, and hope and love bring blessings to others. Grace will naturally flow from the hearts that have been redeemed and sanctified.