The ways in which Heathens use this historical and archaeological material differ; some seek to reconstruct past beliefs and practices as accurately as possible, while others openly experiment with this material and embrace new innovations. Some, for instance, adapt their practices according to "unverified personal gnosis" (UPG) that they have gained through spiritual experiences. Others adopt concepts from the world's surviving ethnic religions as well as modern polytheistic traditions such as Hinduism and Afro-American religions, believing that doing so helps to construct spiritual world-views akin to those that existed in Europe prior to Christianization. Some practitioners who emphasize an approach that relies exclusively on historical and archaeological sources criticize such attitudes, denigrating those who practice them using the pejorative term ""Neo-Heathen"".