GOD SEALED those Who are His and HE DOES THE WORK(S) (by His Spirit) through His tools (HIS SHEEP) that HE put a seal on....
Why is this so hard?
Don't just consider these one or two verses, consider the Scripture in whole.
Scripture verifies Scripture.
Eph 1:13 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,
2Cor 1:21 Now he which stablisheth us with you in Christ, and hath anointed us, is God;
2Cor 1:22 Who hath also sealed us, and given the earnest of the Spirit in our hearts.
2Cor 5:5 Now he that hath wrought us for the selfsame thing is God, who also hath given unto us the earnest of the Spirit.
Eph 4:30 And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption.
Once a son Always a son
I'm aware of all these scriptures.
None of them say the seal can not be removed.
They do say having it guarantees what is to come.
That's why we should retain Christ's seal of ownership by continuing to believe in Him.
'Cause you ain't gettin' nothin' if you get to the Judgment and Christ has removed His seal of ownership from you because you went back to your old life of sin and unbelief:
13All these people died in faith, without having received the things they were promised.
15If they had been thinking of the country they had left,
they would have had opportunity to return. - Hebrews 11:13,15
The old osas says believers, by virtue of being believers, don't have the opportunity to go back.
The new osas says it doesn't matter if they go back to their old lives. The promises are still theirs.
Both are very unBiblical doctrines.