Religion is essentially the core beliefs of a person or group. Often these beliefs concern concepts of a supreme being or god. Religion also deals with peoples values, code of ethics, or treasured ideas.
Misunderstandings, arguments and even wars erupt when a person or group does not respect other's beliefs or uses violence to force beliefs on others. Many cry out for tolerance, others say, "Just be kind."
Often a person's beliefs change as they continue life's journey. Sometimes a person discovers something which is very helpful. Life is often difficult. We can help each other along the way. And we can learn from the mistakes of the past.