What I mean to say is that God, through the Christian’s New Testament, said that the Earth would be destroyed by fire?
I believe this is the verse they are thinking of.
2 Peter 3:10-13
10 But the day of the Lord will come like a thief. The heavens will disappear with a roar; the elements will be destroyed by fire, and the earth and everything done in it will be laid bare.
11 Since everything will be destroyed in this way, what kind of people ought you to be? You ought to live holy and godly lives
12 as you look forward to the day of God and speed its coming. That day will bring about the destruction of the heavens by fire, and the elements will melt in the heat.
13 But in keeping with his promise we are looking forward to a new heaven and a new earth, where righteousness dwells.
Could it be a massive lightning storm of unparalleled proportions? How about a solar storm hitting the Earth?
It looks like the “day of God” and this massive firestorm are on the same day. Correct me if I am wrong.
It could be or perhaps something far worse: the sun expanding, collision between the earth and a large asteroid and etc.
Don't confuse the "end of the world" which comes millennia after the second coming of Christ - according to Revelation and other Bible scripture. That's not to say some of the above doesn't occur during the period of tribulation.
Matthew 24:22 “If those days had not been cut short, no one would survive, but for the sake of the elect those days will be shortened."
You're a rocket scientist; don't take my word for it, continue your own research! :)