2 Corinthians 1:22

1:22 who also sealed us and gave us the Spirit in our hearts as a down payment.

Ephesians 1:13

1:13 And when you heard the word of truth (the gospel of your salvation) – when you believed in Christ – you were marked with the seal of the promised Holy Spirit,

Ephesians 4:30

4:30 And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption.

Revelation 7:3

7:3 “Do not damage the earth or the sea or the trees until we have put a seal on the foreheads of the servants of our God.”