By "invisible" I doubt that you mean simply "unable to be seen with the naked eye," since there are of course many things that are only visible using tools (microscopes, telescopes, infrared cameras, etc.)
By "invisible" you might mean aspects of the world which cannot be sensed with any of our human senses using any technology at all, you have a challenge before you: proving they exist.
Perhaps by "the invisible world" you're referring to abstractions or concepts, e.g. "altruism" or "love" or "evil"? But if so, in this instance I think there must be material evidence for these things for one's belief in them to be rational.
The assertion that an immaterial thing exists, but its existence and any effect of its existence are utterly unobservable, is no different from asserting that the thing does not in fact exist.
So life is effectively purely material. One may assert that there is an unobservable unsensible immaterial reality, but this assertion is ultimately meaningless to us.