Ultimately, we know that the final son of Abraham and Sarah is who blesses all nations and that is Jesus.
And Jesus gives us a sign better than the circumcision given to Abraham. Ours is a circumcision of the heart made inwardly by the Holy Spirit (Romans 2:28). The reason for an inward circumcision is that the true children of Abraham are not the ones who come straight from Abraham’s line, but those who believe in Jesus (Romans 2:29) and are grafted into his line.
And just as Abraham’s circumcision was a sign put on his body guaranteeing the fulfillment of the promise that was to come, the New Testament says that the Holy Spirit’s sign in us is our guarantee that all of Jesus’ promises will be fulfilled as well (2 Corinthians 1:22). “and put his Spirit in our hearts to show that we belong only to him.”
Christians receive a new name as well. In fact, we are renamed twice. The first name is given to you when you put your faith in Jesus. You are made a new creation (2 Corinthians 5:17). At that moment, you are given so many new names: Bride of Christ (2 Corinthians 11:2), Adopted Son or Daughter (Ephesians 1:5) (2 Corinthians 8:16), loved of God: His Saints; (Romans 1:7). The list goes on and on.
There is a second name every Christian will receive as well. The last book in the Bible, Revelation, says that Jesus will give new names to everyone who perseveres to the end (Revelation 2:17). No one knows what this name is or will be. It may be that Jesus gives each of us a private name only he calls us. That’s a name worth looking forward to.
Col 4:6 Let your speech be always with grace, seasoned with salt, that ye may know how ye ought to answer each one. The Bible contains numerous references to salt. In various contexts, it is used to signify the state or quality of lasting or remaining unchanged indefinitely, loyalty, the ability to withstand wear, pressure, or damage, faithfulness to God, demonstrated by continuing loyalty, usefulness, value, and to free from guilt or evil.