Question: Sometimes I can't stop thinking about life after death. I was raised in a religion that teaches that we will live on forever either in hell or in heaven. 
When I think of living forever (even if it is in heaven which should be good), I feel overwhelmed. I don't like the thought of living forever and ever and ever. Sometimes I just can't get the thought out of my mind and the thoughts lead to panic and anxiety. 
Am I crazy? I don't think these thoughts are normal.

Answer: Religious questioning is a complex and often philosophical topic, and these types of questions, especially around heaven, hell, and an afterlife can bring up a host of difficult & confusing feelings. What I want to focus on is the fear & anxiety you seem to be feeling that are deeply connected to your questions. Scary thoughts, negative thoughts, obsessive thoughts sometimes feel like they're out of control and there is nothing we can do to stop them, but I want to offer two techniques that might assist with your panic & anxiety. The first step in working with scary or negative thoughts is to acknowledge that they are just thoughts and we can choose to follow the scary thought streams or work with cutting them off or ignoring them. I also realize that might seem really hard to do, but here's a good way to think about the brain and how thought patterns work. Thoughts arise in the mind all the time, our brain is a thought machine. Many thoughts drift by like clouds and we don't pay any attention while other thoughts arise and they trigger us in a particulate way, i.e., scary, angry, happy, sad, and when those thoughts arise we can chose to pay more attention to the thought which can lead us down that particular thought stream that will lead to fear and anxiety. So, how do we work or stop those scary thought streams? One new skill to implement comes from the work of Rick Hansen, he wrote the book Buddha's Brain," he teaches that we need to give more energy and attention to the positive thoughts or positive memories we hold in our mind and pay less attention to the negative thoughts. Hansen asks us to imagine the brain this way, the brain is like Velcro with negative thoughts and like teflon when it comes to positive thoughts. There are reasons that our brain works this way, but I don't have time to go into all of that in this response. So, it's just important to remember we have to work at positive thinking, actually pausing throughout the day to focus on positive feelings and memories,  this will help the mind reinforce positive thought streams and help reduce negative thought streams over time. If a scary thought arises try to replace it with a happy experience for at least a couple of moments, and see if that helps reduce the negative charge connected with that scary thought. I would also suggest when you're having the thoughts about death take a moment to notice how you're breathing. Often when we are feeling anxiety we are doing shallowing chest breathing rather than taking in a full, deep breath or what is called belly breathing. If you take a moment to focus on your breathing and allow a couple of full breaths, bringing in the breath so the belly rises and then the belly natural falls as you exhale, just noticing the breath and practicing breathing can slow down the anxiety cycle as it begins.