What would symbolize the saying everything happens for a reason?

Causa est omnibus in Latin means 'there is a reason for everything.

The law of cause and effect is known in philosophical

texts also. There is a very specific law in science.

"For every action, there is an equal and opposite

reaction". If you write it in English, it becomes

Newton's Law. If you write it in Sanskrit, it becomes

Law of Karma in Hinduism.