Romans 4:11 And he received circumcision as a sign, a seal of the righteousness that he had by faith while he was still uncircumcised.
Righteousness comes only through faith. Faith in a God who sent His Son to die on a cross for our sins. In the Old Testament the faith was centered on God and His promises. God would instruct the nation of Israel to put in place specific sacrifices and feasts representing God and the future work of Christ.
It started with Abraham
The first connection between God that would be become the nation of Israel was through Abraham. God blessed Abraham for his beliefs in the promises God gave him (Genesis 15:4-6). That process of faith began a work in Abraham that works in all believers. An active righteousness that helps us become more like God and less like fallen man. We will always be wrestling again our human nature but as righteousness increases the power of selfish man decreases. God blessed Abraham to be the father of many nations. But God was also beginning to build a specific nation and bloodline through which Christ would come. So God placed a requirement on Abraham to be a sign and a seal of God’s righteousness for this family line.
Circumcision became an outward sign of a previous faith.
Circumcision became that sign and seal that you are a believer in God. It became an outward sign of a previous inward faith. Those that became circumcised were voluntarily carrying a sign of their faith in God. It was not enough to just believe and no change. Righteousness requires a outward observance. Righteousness requires an outward representation of our choice to believe in God. In Abraham it was circumcision and that would be the sign for the upcoming Jewish nation.
What is the sign of our faith in Christ today?
It is your testimony. It is your outward Christian life. Your becoming a light in a dark world is your sign. You becoming transformed into a new life and turning from your old habits is a sign of the old man being cut off (circumcision). The ministry of Adult and Teen Challenge alike many others are a sign and a seal of what faith in Christ can do. It is their outward sign of an inward circumcision of the old life.
Water Baptism is also a sign and a seal of this transformation through faith. Baptism just like circumcision is not what saves or transforms you. They are signs and seals of God’s righteousness working in you because of your faith.
Your daily devotions and life. Becoming more and more like Christ in your walk, marriage, job, conversation, thoughts, desires are all great signs to all the world of your faith in Christ and your lightnside.