Ephesians 1:13-14

¹³ In Him you also who have heard the Word of Truth, the glad tidings (Gospel) of your salvation, and have believed in and adhered to and relied on Him, were stamped with the seal of the long-promised Holy Spirit.

¹⁴ That [Spirit] is the guarantee of our inheritance [the firstfruits, the pledge and foretaste, the down payment on our heritage], in anticipation of its full redemption and our acquiring [complete] possession of it—to the praise of His glory.

We have been sealed with the Holy Spirit of God, so what or who can penetrate our Father’s Spirit to get to us? Can the devil? Can a demon? Can a man? If anything or anyone could penetrate the Holy Spirit to get to us, what would that make our Father? What good would be our Father’s guarantee of our inheritance if we could be lost? The glorious Truth is that we cannot be lost.

For God’s gifts and His call are irrevocable. [He never withdraws them when once they are given, and He does not change His mind about those to whom He gives His grace or to whom He sends His call.] Romans 11:29

And this is the will of Him Who sent Me, that I should not lose any of all that He has given Me, but that I should give new life and raise [them all] up at the last day. John 6:39