There is no life after death.

• The electrical signals going around our brain determine our thoughts, feelings, and consciousness of the world around us. When we die, it only takes around 10 seconds for all sensory input through those signals to completely disappear, (What Happens to the Brain After Death? (news-medical.net) thus our brain stops, and no memories or consciousness remains to go to an afterlife.
  
• Most religions claim there is a "soul" or "essence" that separates from the body when it dies and goes to the afterlife. Not only do we have no proof of this, but we have knowledge of how we have consciousness with no soul thanks to the theory of evolution and survival of the fittest.
  
• Many of the worlds smartest and most capable people, whom many regard as geniuses, have openly stated that there is no afterlife, (such as Stephen hawking). To claim the existence of an afterlife is to disagree with some of the smartest people this glorified rock has to offer.
  

1. What do we really need to prove our side correct?
   

There is no life after death.

Afterlife- An existence after death.

Death- A permanent cessation of all vital functions: the end of life.

1

: continuing or enduring without fundamental or marked change : STABLE

2

a

: not easily removed, washed away, or erased : INDELIBLE sense 1a

b

: making marks that cannot easily be removed : INDELIBLE sense 1b

• According to entry 1, yes, because when an entity is dead, without external intervention, it stays dead, stabily and persistently.
  
• According to entry 2, yes, because saving individuals from death is a difficult task with low success rates(but not zero). Source here.
  

Clinical death is reversible. Researchers believe there's a window of about four minutes from the moment of cardiac arrest to the development of serious brain damage.1 (as you can probably imagine, that's a pretty hard statistic to validate through a random control trial).

If blood flow can be restored—either by cardiopulmonary resuscitation (CPR) or by getting the heart pumping again—the patient could come back from clinical death. It's not a sure thing; success rates for CPR are pretty dismal.

• PRO: The electrical signals going around our brain determine our thoughts, feelings, and consciousness of the world around us. When we die, it only takes around 10 seconds for all sensory input through those signals to completely disappear, (What Happens to the Brain After Death? (news-medical.net) thus our brain stops, and no memories or consciousness remains to go to an afterlife.
  

Biological death, on the other hand, is brain death, and there's no turning back from brain death.3 That is irreversible death.

Just to make things a bit more complicated, however, it is possible to keep the body alive while the brain is dead. The heart is more of a subcontractor than an employee of the body; it keeps its own hours and works without direct supervision by the brain.

Since the heart works without brain input, it's possible to keep it going for a long time after the brain is dead. Indeed, that's one way that organ donation happens.

Technically, clinical death requires both the heart and the breathing to stop, but that's just semantics. Breathing and consciousness will cease within a few seconds of the heart stopping.

Clinical death is reversible. Researchers believe there's a window of about four minutes from the moment of cardiac arrest to the development of serious brain damage.1 (as you can probably imagine, that's a pretty hard statistic to validate through a random control trial).

• PRO: Most religions claim there is a "soul" or "essence" that separates from the body when it dies and goes to the afterlife. Not only do we have no proof of this, but we have knowledge of how we have consciousness with no soul thanks to the theory of evolution and survival of the fittest.
  

• PRO: Many of the worlds smartest and most capable people, whom many regard as geniuses, have openly stated that there is no afterlife, (such as Stephen hawking). To claim the existence of an afterlife is to disagree with some of the smartest people this glorified rock has to offer.
  

• Asking a Nobel Laureate in Chemistry(that is alive, of course) of which candidate he/she/they will support in the next US president election, then conclude that that candidate answered will win just because an expert expressed support, regardless of the level of compatibility within the fields.
  
• Asking the US president advanced quantum mechanics and string theory questions that require excruciating lengths in mathematics and physics to do assuming the US president does know the answer, then get disappointed because they discover the US president hasn't learned such because they didn't need such niche knowledge to run the country(regardless if they did a good job, I assume they did a better job than me though.).
  
• Taking Terence Tao on a TV show without telling him what it is about then asking him questions about the latest netflix show. Seriously, do you think he can answer it?
  

• Revival technologies from clinical deaths(which are valid deaths) ensure that an afterlife exists.
  
• Stephen Hawking and others with incompatible fields do not count as valid appeal to authority.
  
• I rest my case.