“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, which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory.” Ephesians 1:13-14 (KJV)
We need not be fearful that God will not fulfill His Word. He has promised that He will finish what He has began (Philippians 1:6). There is nothing that can separate us from the love of Christ Jesus (Romans 8:35-39). Best of all we have God’s “Earnest” payment that He will do it.
“Earnest” is a real estate term. One puts down an earnest payment as a guarantee of payment of a down payment on a house or land. The Holy Spirit is God’s gift to us as promise, evidence that He will complete what He has began in us. You will note too, that “Ye were sealed with that Holy Spirit of promise”.
In Christ we are a sealed document, that cannot be opened until it is delivered into the hand of the King. Please read Romans 8:9.