Life is Suffering
Life has been defined as suffering by so many different individuals during the history of mankind, from the Veda and Buddha to philosophers like Arthur Schopenhauer, E.M. Cioran, Ulrich Horstmann, David Benatar and countless others, that I don't even know where to start. First of all, every form of life that we know is in itself just a tiny, insignificant individual in a universe of infinite space and time, bound to a body, forced to fulfill desires and urges for a short time, just to keep the need-machine running and fall back to other forms of desire. Furthermore the biggest problem of sentient life in general is the ability to feel pain in all forms and variations from mild mental pain to extreme physical pain and mutilation. "Happiness" can pretty much be defined simply as a state where all the negative aspects, like pain, hunger and desire are absent, a state which usually leads to bordedom (another form of suffering) very fast, so the state that seemed to be the goal and meaning of life turns then out to be a state that can only be maintained a very short time before it gets replaced by boredom which makes new needs attractive or, even if boredom doesn't come up, gets replaced by new needs anyway. All this means that life is an eternal hunt for the ideal state of the individual, which, as soon as reached, turns out to be an illusion or at least a very short period of fulfillment.
Death is Redemption
Death is redemption for one obvious and very simple reason: It ends life. Ironically, the only way to truly fulfill all desires of life is to end it. Of course, nature took care of that and made sure that death, even though it is obviously the solution to all of lifes problems, is the most horrific thing to imagine for living beings and nothing gets feared more instinctively by animals and consciously by humans, then death. It's pretty absurd that the only secure solution for everything seems to be the one thing that has to be avoided at all costs. I'm sure, if there wouldn't be these frightening guardians at the exit door, suicide would be the most common thing on earth, or maybe mankind would even have ceased to exist ages ago. But as it is, for almost everyone even the most awful horrors of life seem to be better than the horror of death.
Affirming the Will to Die
Philipp Mainländer introduced the will to die to the world of philosophy. While his role model Schopenhauer defined the will to live as the driving force of the world, Mainländer stated that in fact the will to live is just a mask for the will to die (this has been pointed out in detail in my essay "The rotting God"). While Schopenhauer only left the options of affirming or denying the will to live, Mainländer introduced another option, which is the affirmation of the will to die. Of course, affirming the will to live automatically comes with denying of the will to die. But denying the will to live does not automatically lead to affirming the will to die. Denying the will to live has been defined by Schopenhauer mainly as living in askesis and reclusion. But Mainländers option of affirming the will to die goes beyond that. It means not only to say no to life by resigning from it, but also to say yes to death by acknoledging suicide as the solution for life and by realizing that death is in fact the meaning not only of life, but of the entire universe (this has also been stated in detail in the "rotting god" essay). So when Mainländer says: "The sign of our flag is not the crucified saviour, but the death angel with huge, calm, mild eyes, carried by the dove of the redemption thought" this is exactly the affirmation of the will to die that he means. This death angel he describes is not a frightening guardian, but a sympathetic redeemer. Mainländer does not order his followers to commit suicide, but he invalidates all arguments that are speaking against it.
I recently came up with the idea of calling this will-to-die-affirming ideology "Entroptimism" (a combination of the words "Entropy" and "Optimism"), because Mainländers philosophy goes beyond antinatalism and efilism. It doesn't only deal with life, it deals with the entire universe. Like described in the other essay, the whole universe is rotting to nothingness and life is just a worthless byproduct that rots to nothingness in a special, but worse way then the rest, because it is sentient. Since there is absolutely no hope for anything in this entire universe, the only reaction to it is absolute pessimism. But - If "somethingness" means 100% hopelessness, then nothingness means 100% hope. If somethingness is hell, nothingness must be heaven, because it's the opposite of somethingness. Therefore, the only reason to be optimistic in this universe, is the fact that it will turn into nothingness, that every single part of it will be redeemed forever by the universal death angel called entropy.