For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
If we do have an appointed time of death and can't do anything to change that time then that would seem to indicate that we have no ability to make any choice or have free will.
I've always been told that we can go before our time. If we (Christians) live as a bad testimony, He will take us home before our time. It's up to us to live properly and for Jesus as testimonies for the lost, but if we cannot do this, God will take us home.
Ataloa, I believe the verse that you are referring to is:
1 Corinthians 5:5 (ESV) – Regarding a man living in sexual immorality:
"You are to deliver this man to Satan for the destruction of the flesh, so that his spirit may be saved in the day of the Lord."
This implies that God may allow a believer’s physical death due to persistent sin, but their salvation remains secure. Am I right?