Some believe that there is no metaphysical: no god, no heaven - just the material universe. This itself is a metaphysical truth claim that is not falsifiable. It takes faith in certain things to believe this.
Others believe that there is a metaphysical, but that it is impersonal and must be actualized through your actions or ritual. This is also not a falsifiable claim, and takes faith in certain things.
Still others believe that not only is there a metaphysical, but that a Person created the physical universe and has revealed Himself in history and in nature and that He may be discovered through examining these things. Also not falsifiable and takes faith in certain things.
If you are interested in exploring this last avenue, may I suggest reading: