People believe in those things because they need to but there is not a single piece of evidence supporting heaven/god. ''On the contrary many people know there is a higher meaning and purpose'' They think they know but it doesn't mean they do. They think the purpose is to go to heaven but they never think what is the purpose once you are in heaven or what is the purpose once you are reincarnated. It doesn't seem to me that there could ever be a good purpose because what happens once you reach it? Perhaps we can't understand it now because our brain is not capable of understanding but imagining gods is not going to do anyone any good.
The whole earth and universe is proof for the existence of God. You ask, indirectly: "They think the purpose is to go to heaven but they never think what is the purpose once you are in heaven or what is the purpose once you are reincarnated." But you can't even figure out a purpose for life here.
Stuff doesn't just happen anywhere. If people don't make it happen, what does? There is too much order and complexity in all of it, to say nothing about cause-and-effect, strict, rigidity of everything, to say that it happens by chance or accident. BTW, "chance" has only been found in things that people are too ignorant or incapable of understanding the true cause for.
There isn't any chance in anything. Everything is planned and programmed. Complexity points at God. Religion explains the things of God that science is to inadequate to do. God answers by providing health to the religious people.
EDIT: The sperm and egg go on to life as an embryo; the embryo goes on to life as a fetus; the fetus goes on to life as person; the person goes on to real life in Heaven. If the person goes to Hell, consider that not all sperm or egg go on to embryo; not all embryo go on to fetus; not all fetuses go on to people. And some people never become smart enough to make it to Heaven.