With out getting into the million what if just sticking to these . Peter denied Christ three times... The only what if i am thinking about is what if Pete had a heart attack and died a physical death at that time . Could in be God called him home? Could it be damnation. Could Pete's death be be in control of his salvation?
The problem for those that do not believe in OSAS, is a misunderstanding of
Positional Sanctification and
Conditional Sanctification.
In the simplest terms - What God has Justified (Positional Sanctification), cannot be superseded or destroyed by ones "Condition".
Do not go crazy with this. A true believer, has no desire to live like "hell". Therefore, if someone is living in "Sin", they are not true believers but mere religionist.
There really should be NO debate over this subject. A simple read of the Scriptures proves OSAS. Look at what Christ said here:
John_6:37 All that which the Father gives to me shall come unto me; and him that cometh to me I will in no wise cast out.
This clear and concise statement - Father gives to me and I will not cast out - requires no particular conditional requirement. This says God "will do" it.
Any passages of Scripture, that seem to say otherwise, must be "harmonized with this one clear statement in John 6:37. God is not confused nor is He the author of confusion. Likewise, the Word of God does not establish a thing in one place and then erase a thing in another place.