In the Bible it is positive, as being sealed for entrance into heaven.
2co 1:22 Who hath also sealed us, and given the earnest of the Spirit in our hearts.
Eph 1:13 In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,
Eph 4:30 And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption.