“…ye were sealed with that Holy Spirit of promise.” Ephesians 1:13
The moment you receive Jesus Christ as your Lord and Savior, the Holy Spirit of God seals you into Himself.
What does it mean to be “sealed”? It means the King’s seal has been placed on you. The King’s seal can be broken by no man. That means you are His for all time and eternity.
Second Timothy 2:19 says, “Nevertheless the foundation of God standeth sure, having this seal, The Lord knoweth them that are His.” You are sealed into a relationship with God by the Holy Spirit.
Read Daniel 6 and Matthew 27. Note the similarities in the accounts of Daniel and Jesus being sealed away for death—and how the Almighty God delivered them unto life!