«No one who performs a mighty deed in my name who can at the same time speak ill of me».
Today Jesus speaks up for someone who, despite not being part of His group, made miracles. John wanted to forbid it... In the world there are many good people who, perhaps, are not Christians or believers. Let us not drive them away or be driven away, let us learn from them! Let us work with them! On the other hand, Jesus Christ is very severe with those who can do harm by setting a bad example, "it would be better for him to have a great millstone hung around his neck and to be drowned in the depths of the sea".
-Give a good example! Everyone! The eldest to the youngest, and the youngest to the eldest (because we always have much to learn).