What you missed that the necessary change happens specifically at the last trump, and no other time.
If we turn away we lose, for eternity. That is what Hebrews 6 and 10 say in plain words. There is no ace in the hole for salvation, but to endure to the end.
Hebrews 6:The words are there in several epistles, by different authors, and there is no room for OSAS in any of them.
[4] For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost,
[5] And have tasted the good word of God, and the powers of the world to come,
[6] If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.
Salvation is at the last trump; that is why Yehova made his most distinctive appointed day, Yom Teruah, to watch for it.
That is why Yeshua said in Revelation 3:
[3] Remember therefore how thou hast received and heard, and hold fast, and repent. If therefore thou shalt not watch, I will come on thee as a thief, and thou shalt not know what hour I will come upon thee.
And Paul assured the Thessalonians that Yeshua would not come to them as a thief, because they diligently kept his feasts.
Its all there in the book for those who care enough to want to know. If you prefer to 'know' something that really is not there, you're on your own, for eternity
Is your name to be found written there?