Two Kinds of Sealing (Ephesians 1:13-14)

I wrote this piece back in 2012 on another forum; edited 9/18/23.

A friend recently asked me about the subject of "sealing" in the Bible. For example,
"in whom ye also, having heard the word of the truth, the gospel of your salvation,-- in whom, having also believed, ye were sealed with the Holy Spirit of promise, which is an earnest of our inheritance, unto the redemption of God's own possession, unto the praise of his glory" (Ephesians 1:13-14 ASV).

Notice that the Ephesians "were sealed" (past tense) with the holy spirit. But if they were sealed in the past, then why does the Bible indicate that a future sealing will occur? See Ephesians 4:30; Revelation 7:1-8.

A beloved Christian sister once explained to me that there are two phases of God's sealing. Jehovah seals a Christian when he/she is anointed, but the seal must be kept until death or the system's end (2 Corinthians 1:22; 5:1-5; Matthew 24:13; James 1:12; Revelation 2:10). When anointed, the seal is written with a pencil (so to speak), but the final sealing is done with a pen that is made of indelible ink. I always liked her explanation. It helped me to see how there could be two phases to the divine sealing carried out by Jehovah. See also Romans 8:23.