I think you non OSAS people need to explain the following verses.
Romans 11:29
29
For God’s gifts and His call are irrevocable.
2 Corinthians 5:17
“Therefore, if anyone is in Christ, he is a new creation; the old has gone, the new has come!”
So, then would a new creation be turned back into an old creation again? And then repents and becomes a new creation again? Does this happen over and over and over?
1 Peter 1:18-19
“For you know that it was
not with perishable things such as silver or gold that you were redeemed from the empty way of life handed down to you from your forefathers,
but with the precious blood of Christ, a lamb without blemish or defect”
So is Christ's blood then perishable? Can it perish and be lost? The Word of God says it is NOT PERISHABLE.
John 3:16
“For God so loved the world that he gave his one and only Son, that
whoever believes in him
shall not perish but have eternal life”
Ephesians 1:13–14
13 In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him,
were sealed with the promised Holy Spirit, 14
who is the guarantee 14 of our inheritance until we acquire possession of it,to the praise of his glory.
Titus 1:2
2 in hope of eternal life, which God,
who never lies,
promised before the ages began
1 Corinthians 2:19-20
19 Do you not know that your body is a temple of the Holy Spirit who is in you, whom you have received from God?
You are not your own; 20
you were bought at a price.
There is more, but we can start there.