What are the authentic hadiths mentioned concerning the the virtues of Rajab, Sha'ban, and Ramadan, and are people freed from Hellfire in Ramadan, and does that mean that the one freed will never enter Hellfire again, no matter what they do?

Fasting Ramadan is an obligatory act and a pillar of Islam. In it, good deeds are multiplied, the gates of Paradise are opened, the gates of Hellfire are closed, and the devils are chained. Regarding its virtue, it has been reported that "Whoever fasts Ramadan out of faith and hope for reward, his past sins will be forgiven." It seems that whoever is emancipated from the Fire in this month will never enter it.