“But he will give you relief from your troubles. He will do the same for us, when the Lord Jesus comes from heaven with his powerful angels and with a flaming fire. Our Lord Jesus will punish anyone who doesn’t know God and won’t obey his message. Their punishment will be eternal destruction, and they will be kept far from the presence of our Lord and his glorious strength.”
2 Thessalonians 1:7-9
A fire can be beautiful, warm and comforting, or it can be frightening, painful and destructive. It all depends on what you are made of and how close you are to the fire. If you are "fireproof" then you won't burn no matter how close you come to the fire. Then the fire will simply burn away the impurities, the things that will burn and it will leave you pure and holy, devoted to God.
If your basic nature has never been converted into one that can withstand the flames, the fire will consume you and bring about your eternal destruction and separation from God.
You see, what happens when you have faith in Jesus Christ is this: He changes you into someone that the fires of Hell cannot touch! You will become like Shadrach, Meshach and Abednego who were thrown into the fiery furnace and came out not even smelling like smoke.
The fire of Heaven will make you Holy and keep you far away from the fire of Hell!