One reason Buddhism is not more popular, one suspects, is that it makes various claims that strike people as wildly implausible at first glance.
If I am not my body, who am I? Apparently, in Christianity, the important part of any human is the soul, although Christians do tend to fetishize dead bodies, spending thousands of dollars to preserve them as long as possible, even though those efforts will certainly fail eventually.
According to the Buddha, again, pretty much all of human life is a fundamental misrecognition. Your slice of consciousness is attached to your current body for some period of time, but we know that your current body will cease to function at some point — you will die — at which time your consciousness will dissipate completely (my interpretation of what happens to persons who are awakened), or it will find another lifetime and get born yet again in samsara.
It is really very interesting to notice that your attachment to your body is temporary. Again, a central message of the Buddha is that we know we are going to die eventually, so we should use the time until then to prepare for that inevitable event.
Meditation is the best way to prepare for death.
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