In Him you also trusted, after you heard the word of truth, the gospel of your salvation; in whom also, having believed, you were sealed with the Holy Spirit of promise who is the guarantee of our inheritance until the redemption of the purchased possession (Ephesians 1:13-14)
Satan is the author of doubt…and doubt is the opposite of faith. If you accept Jesus Christ as your Lord and Savior, you are signed, sealed and in route to your eternal inheritance. This is a guarantee underwritten by the Holy Spirit. Believe it!