Does God protect whoever prays for forty days in congregation, catching the first Takbirat al-Ihram, from hypocrisy and hellfire for the rest of his life, even if he lives long, and even if he does not continue praying in the same manner thereafter? And would this short period be a cause for his entry into Paradise through protection from the Fire?

A person's negligence in prayer is a satanic trick, and believers should not be deluded by their good deeds; rather, they should fear their non-acceptance. The authenticity of the hadith: "Whoever prays to Allah for forty days in congregation, catching the first takbir, two immunities will be written for him: an immunity from Hellfire and an immunity from hypocrisy," is disputed. Even if the hadith were authentic, the intended meaning of immunity from hypocrisy is that Allah safeguards the servant from the deeds of hypocrites and grants him success in performing the deeds of the sincere, not that one should cease worship thereafter.