James,
There is not a hint anywhere in John chapter 5 and 6 saying anything about millennial, because it doesn't saying "a thousand years".
John 6:39,40,44, and 54 telling us very clear that there shall be a resurrection on "last day" of this present age at Lord's coming.
Also, "kingdom of God/heaven" in many passages of the Bible never called it, 'millennial kingdom', because none of these saying, 'a thousand years'.
For example - John 3:3 tells us, that we must be born again, or cannot see the kingdom of God. Christ means that we must be repent of our sins, or we cannot have eternal life. Christ doesn't saying, you must be born again, or you cannot enter a thousand years of the kingdom.
There is no scripture in the Bible saying anything about purgatory or temporary punishment. Obivously, Christ warns us if we do not repent or not obey God, shall be punishment and be separated from God forever and ever at the judgment day.
Matt. 25:30 is very clear telling us, if a servant hide his/her a talent and not use it or disobey God, will be cast into everlasting punishment separated from God at the judgement day. Matt. 25:30 doesn't suggest us that a lazy servant shall be suffering for only a temporary, because Christ doesn't saying it is a temporary. Use our common sense and understand what Christ was talking about.
Matt. 25:30 is much same with Matt. 25:41 speaking of fire is an everlasting, not temporary. Even also Matt 25:46 too.
In Christ
Rev. 22:20 -Amen!