It is so very awesome that God has put His signature on the promise made by the Holy Spirit! WE ARE SEALED WITH HIM!
WE ARE ETERNALLY SECURE!
ONCE SAVED, ALWAYS SAVED!!
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,
14 Which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory.
Ephesians 1:13-14 (King James Bible)