The teaching of Purgatory is based on a passage from the non-biblical book of 2 Maccabees, which is not part of the divine, inspired Scriptures, and therefore not the same in authority as the 66 Books of the Holy Bible. This teaching is nowhere to be found in the entire Bible, even though there are some who suppose that it does. The New Testament Book of Hebrews, is very clear that after a person dies, only the Righteous Judgement of God awaits them: " And just as it is appointed for people to die once and for all and after this, judgment" (9:27). Salvation is not possible after death. All those who leave this world as "born-again believers", through repentance of personal sins, and faith in Jesus Christ as their personal Saviour, are "saved" and will spend eternity in heaven with the Lord. All who die "in their sins", that is, without Jesus Christ as their Saviour, will end up in "hell", which Jesus describes as a place of suffering (wailing and gnashing of teeth - Matthew 13:42, etc), "where their worm does not die and the fire is not quenched" (Mark 9:48). Note the use of the personal "their" (both in the Hebrew [Isaiah 66:24] and Greek) "worm", which is a reference not to the "creeping animals", but to the person [body] (Isaiah 41:14).
On Gehenna, "is strictly "the valley of Hinnom" (Jos 15:8; Ne 11:30); "the valley of the children of Hinnom" (2Ki 23:10); "the valley of the son of Hinnom" (2Ch 28:3); "the valley of dead bodies," or Tophet, where malefactors' dead bodies were cast, S. of the city (Jer 31:40). A deep narrow glen S. of Jerusalem, where, after Ahaz introduced the worship of the fire gods, the sun, Baal, Moloch, the Jews under Manasseh made their children to pass through the fire (2Ch 33:6), and offered them as burnt offerings (Jer 7:31; 19:2-6). So the godly Josiah defiled the valley, making it a receptacle of carcass and criminals' corpses, in which worms were continually gendering. (Fausset’s Bible Dictionary)
“The LXX does not have γέεννα. Joseph. mentions neither the term nor the matter, probably because he was a Pharisee and thus denied the resurrection of the ungodly (Bell., 3, 374 f.; Ap., 2, 218). Philo does not know the word and uses τάρταρος instead (Exsecr., 152).7...It is significant that the oldest Rabbinic reference to Gehenna (T. Sanh., 13, 3 and par.) tells us that the disciples of Shammai, as distinct from those of Hillel, ascribe to Gehenna a purgatorial as well as a penal character, namely, in the case of the שְׁקוּלִים or בֵּינוֹנִים, i.e., those whose merits and transgressions balance one another. It may be that this conception of a purificatory character of the final fire of judgment underlies such passages as Mk. 9:49; 1 C. 3:13–15; cf. 2 Pt. 3:10." (Kittel TDNT)
The Greek Old Testament, which was completed some 150 years before the Birth of Jesus Christ, does not have the word "gehenna". The Jewish Philosopher, Philo (25 B.C.-A.D.50), never used the word. Nor does the Jewish historian Josephus, who lived just after the death of Jesus (A.D.37-100).
In my own study on "γέεννα", I found that the majority of its uses in the New Testament, it is used in connection with believers, as in Matthew 5:22, 25, 30; 10:28; 18:9; 23: 15, 33; Mark 9:43, 45, 47; Luke 12:5, and James 3:6. It is clear from the teachings in the New Testament, that those who are truly "born-again" believers in the Lord Jesus Christ, can never be lost in hell, but are guaranteed heaven after they die. I cannot understand the use of "γέεννα" for this group.