The law of cause and effect can be explained as the relations and conditions which must be present for phenomena and occurrences to take place. Without these relations and conditions, nothing will actually happen.
We exercise our free choice and descend from the spiritual plane to the material plane.
“This reminds me of the story of the grieving person who comes to the Buddha to ask for relief. Buddha tells them to go to all the houses in the village and ask for a seed from every household that has never experienced death. The person does so and finds that every single home has experienced what they are experiencing, even if the details are different.”