Ephesians 1:13
In whom ye also [trusted] after ye had heard the word of truth, the gospel of your salvation; in whom also, having believed, ye have been sealed with the holy Spirit of promise,
Ephesians 4:30
And grieve not the holy Spirit of God, whereby ye have been sealed unto the day of redemption.
2 Timothy 2:19
Nevertheless the stable foundation of God standeth firm, having this seal, the Lord knoweth those who belong to him. And, let every man who mentions the name of the Lord depart from unrighteousness.
Revelation 7:2
And I saw another angel ascending from the rising of the sun, having the seal of the living God; and he cried with a loud voice to the four angels to whom power was given for them to hurt the earth and the sea,