A rule I have had for years is: to treat the Lord Jesus Christ as a personal friend. His is not a creed, a mere doctrine, but it is He Himself we have.
We are told to let our light shine, and if it does, we won't need to tell anybody it does. Lighthouses don't fire cannons to call attention to their shining - they just shine.
It is a masterpiece of the devil to make us believe that children cannot understand religion. Would Christ have made a child the standard of faith if He had known that it was not capable of understanding His words?
Preparation for old age should begin not later than one's teens. A life which is empty of purpose until 65 will not suddenly become filled on retirement.