Ephesians 1:13
And in Him you Gentiles also, after listening to the Message of the truth, the Good News of your salvation--having believed in Him--were sealed with the promised Holy Spirit;
Ephesians 4:30
And beware of grieving the Holy Spirit of God, in whom you have been sealed in preparation for the day of Redemption.
2 Timothy 2:19
Yet God's solid foundation stands unmoved, bearing this inscription, "The Lord knows those who really belong to Him." And this also, "Let every one who names the Name of the Lord renounce all wickedness."
Revelation 7:2
And I saw another angel coming from the east and carrying a seal belonging to the ever-living God. He called in a loud voice to the four angels whose work it was to injure the earth and the sea.