I like the Buddhist theory that we will pop back into existence as something or someone else

Would never like there's no afterlife.
Imagine all those war criminals just turn up to nothing, and all oppressed also turn up to nothing.
The murderer and theif turn up to nothing, after they escaped in this life.
What an unfair world we live in
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The afterlife is coming where the complete justice takes place (a reward or a punishment)

If eternal damnation awaits most people then surely it would be best that there isn't an afterlife?

most? how do you know that?
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What is waiting everone is the perfect justice, not damnation.
Well, it is even mercy of Almighty will be more and above in the day of resurrection.
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Abu Hurairah (May Allah be pleased with him) reported: Messenger of Allah (PBUH) said, Allah has divided
mercy into one hundred parts; and He retained with Him ninety-nine parts, and sent down to earth one part. Through
this one part creatures deal with one another with compassion, so much so that an animal lifts its hoof over its young
lest it should hurt it.
[Al-Bukhari and Muslim]
Another narration is: Messenger of Allah (PBUH) said, Allah has one hundred mercies, out of which He has sent
down only one for jinn, mankind, animals and insects, through which they love one another and have compassion
for one another; and through it, wild animals care for their young. Allah has retained ninety-nine mercies to deal
kindly with His slaves on the Day of Resurrection.''
[Al-Bukhari and Muslim].

Commentary:
1. We learn from this Hadith that kind and compassionate treatment is liked by Allah and is in fact His Blessing and
Benevolence. This is the reason He has given a part of it to His creatures..
2. On the Day of Resurrection, Almighty Allah will bestow upon the believers hundred mercies. This news has great
hopes and joy for His slaves.
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Just be in the right side, have the right belief, and try your best in the path of good.
Then, the joy and success you'll ultimately get is above and beyond expectations.

You die and it's like you are asleep. You're just not conscious anymore. Remember before you were born? No, because you weren't alive

None of this justice bo11ocks I'm afraid

Afterlife is just a fairytale for adults whose ego cant cope with dying one day. It is not doing any good to anyone. Better to invest in this life here and make peace with the fact that everything ends at one point. A much more mature way to live.

Rather take a limited life with a end that gives time you have worth than a unending boredom fest. Things get worse when there is too much of it. Like one of those tv shows that keeps on going versus those with a nice ending.