The point of a fortune is not to take it with you, but to use it in the most joyful, creative, and effective ways possible while you are here...which should benefit both yourself and others if you do it well and wisely. Money's just a tool. Nothing more. As I recall, Jesus was making a particular and very clever maneuver with that statement you quote...he was deflecting an attempted attack on him by the religious hierarchy of his time. They were trying to entrap him in some supposedly wrongful behaviour, so they could discredit or destroy him. He evaded their trap in a way they did not anticipate when he gave that answer.

In truth, everything is God's...because God is the intelligent energy out of which everything is made...period. Nothing is ours, except our conscious awareness of self. Everything we think we own is temporarily borrowed, and we can't take any of it with us. We can only experience it while we make use of it here and now.