I won't say am a religious person, but i'll definitely pass for someone who belongs to a religion. However, it doesn't take a religious person to believe in life after death. I think the right word in religion is resurrection.
According to the two major religions, Islam and Christianity, resurrection is when the dead gets risen again to face judgment. Hence, it's completely upright for a religious person to believe in life after death as both religion clearly shares the same view on the subject.
Asides religion, many other school of thoughts have brought forth theories on the subject of life after death. Although most of these theories do not align with religious views, they tend to all believe in the concept of rising again.
Some school of thought term life after death as a process which involves the soul leaving the body behind to continue living, or existing in a world unknown to the living. This theory is quit different from resurrection which is rising the dead again. They further prove this theory by pointing at ghosts which is evidently the soul of a dead person. This theory is widely rejected because most people do not even believe in the existence of ghost which is the primary prove to the theory.
On a more radical thought, another theory puts life after death as a form of reincarnation. Although a lot of people have come forward with compelling stories which proves they were reincarnated, this theory still lacks basis as no one knows for sure if those people were actually reincarnated, or they just happen to have and share certain memories of a former living person. Think of it like a cluster, or an interferance betwenn radio active gadgets. But yet, humans are not brought to life through a programmed pricess. So maybe there's a possibility of reincarnation. Another problem with this theory is that, if every human gets reincarnated after living a previous life, then majority of living humans should have some type of memories from our previous past. And like I said earlier, although a few people have come forward with such memories which were actually comfirmed, it's still a bit sketchy as very little percentage of people have had this experiences.
Anyawyas, which ever way you look at it, life after death is a possibility in my opinion. There has to be something after death.