We Buddhists believe in birth following after birth. Some people have a hard time accepting this. However, just because we cannot see something, does not mean that it is not there. Just because we have not found something does not prove its nonexistence. And if reincarnation is true and we do not prepare ourselves, we could be taking a big risk. If we spend all our strength on this life only, and suddenly the scientists find out that indeed there is a next life, it might be too late for us. So we have to think carefully.

--17th Karmapa, Ogyen Trinley Dorje