Here is a fun logic puzzle for those who follow the Theology of Dante's Inferno or Paradise Lost. If you believe the story of Lucifer as told in those tales reflects reality, then I can prove to you that everyone eventually ends up in Hell, given 4 simple premises. The premises go as follows:
There are only 2 locations for a human soul after life: Heaven or Hell.
Hell and Heaven are both eternal
It is possible to be cast out of Heaven for sinning
You cannot leave Hell once you are in it
Now let's follow the path of a human soul on earth. When the person dies, there are two possible destinations according to premise #1, so let's first examine someone who is initially placed in Hell. Well, according to premise #4, a person placed in Hell will never leave. So as time goes to infinity, they will always remain. Pretty simple.
Now let's examine someone initially placed in Heaven. Premise #3 says that there is a possibility to be sent out of Heaven for choosing to sin. The probability of choosing to sin might be minuscule, and maybe the sin has to be huge to actually be thrown out. For example, maybe it would require choosing to reject God despite being in his presence. Or maybe it would take an active rebellion against God despite knowing he is all good. All these are unlikely actions given what people assume about heaven, but the fun part about eternity is that as long as the possibility is non-zero, then eventually you WILL do it. Even if Heaven is lenient and has a 3-strike system so you are okay if you only do it once, you will eventually - given enough time - do it again. It doesn't matter how many strikes it takes, the reality of eternity is that you will eventually do everything within your ability an infinite amount of times. So, no matter how long it takes, if it IS possible to be tossed from Heaven for sinning, then you WILL be cast down to Hell eventually, along with everyone else.
The only way to avoid this final situation is to not believe in one of the 4 premises I shared at the beginning. I'm sure there are plenty Christians who will disagree with one or more of the premises. But I will say now, that there are also definitely some Christians out there that do agree with all the premises, and to them I say: you may want to rethink your position.
Note: To those who will inevitably say "it's possible to choose to sin in heaven but we would never choose that"... that's the same as it not being possible to sin. If our "logic" (or "will", if you will) always results in the same answer, then we would be no different than a machine. Either it is possible that we can choose to sin - and therefore, inevitable, given an eternity - or it is not possible and no one will ever be cast out of Heaven.