It is by the act of baptism that a person enters into a blood covenant with God. Water baptism in Jesus name is compared to circumcision. Circumcision is a blood covenant. (Circumcision, in order to be  Halakhic, requires the shedding of a drop of blood).

"In whom also ye are circumcised with the circumcision made without hands, in putting off the body of the sins of the flesh by the circumcision of Christ: buried with him in baptism, wherein also ye are risen with him through the faith of the operation of God, who hath raised him from the dead." - Colossians 2:11-12 KJV

("When you came to Christ, you were "circumcised," but not by a physical procedure. Christ performed a spiritual circumcision--the cutting away of your sinful nature. [Greek: the cutting away of the body of the flesh.] For you were buried with Christ when you were baptized. And with him you were raised to new life because you trusted the mighty power of God, who raised Christ from the dead." - Colossians 2:11-12 NLT)

In the Old Testament, if a man did not enter the covenant of circumcision, he was cut off from the people of God, for he had broken God’s covenant.

"And the uncircumcised man child whose flesh of his foreskin is not circumcised, that soul shall be cut off from his people; he hath broken my covenant." - Genesis 17:14 KJV

("Any male who fails to be circumcised will be cut off from the covenant family for breaking the covenant."" - Genesis 17:14 NLT)

In the New Covenant of Jesus Christ, physical circumcision is no longer required. In the New Covenant, we must repent and be water baptized in Jesus name to be saved. When we are baptized in Jesus name we enter into a blood covenant with Jesus. Just as the flesh had to be cut off in Old Covenant circumcision for them to be saved, our sinful nature must be cut off in the New Covenant by repentance and baptism in Jesus name to be saved. Our sins are cut off/washed away/remitted/forgiven when we are baptized in Jesus name.

Peter preached the gospel on the day of Pentecost – Jesus’ death, burial, and resurrection – to the multitude that gathered.

"Now when they heard this, they were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do?

“Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.

“For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call." - Acts 2:37-39 KJV