Being an agnostic existentialist, I make a conscious effort to stay as rooted in vital existence as is psychologically and emotionally feasible. It is my belief that there is no intrinsic value/meaning of Life or Existence, nor can any ideology be morally quantified as being "a truth" or "a lie". Vital existence is living in the here and now - perceiving reality without delusional filters to cloud One's judgement. These perceptions are based on a combination of personal experience and objective inquiry/empirical evidence. It is a fact, though, that every human holds some form of a delusion as a perceived "truth" and believes that their perceptions come as a result of/result in some form of "spiritual truth".
Because I don't concern myself with the possibility of an afterlife, my actions are guided by my natural instincts - my desires, disdains, experiences and "gut feelings". In addition, I pay no mind to the whims of those around me - "authority figures", peers, or social/cultural "norms". These are the essential ingredients in what I have deemed "Belialic Magick". Belial, as defined by Anton LaVey in The Satanic Bible, means "Without a master" in the Hebrew language. In order to become a successful Belialic magus (or, magician), One must act without the feelings of guilt or embarrassment weighing down on Their inherent freedom of choice.
While I don't concern myself with the possibility of a metaphysical afterlife, I do believe that immortality is attained by way of projecting One's consciousness/willpower into Their social sphere.