If extraterrestrial intelligence (ETI) exists elsewhere in our universe, any meaningful and absolute confirmation would require either a transformative announcement, global broadcast, single fantastic irrefutable event experience, or acknowledgment of a large accumulation of increasing evidence which equates to that historical revelation. The Humaniverse Guide to First Contact with ET embarks on an exploration of how ETI is viewed by theologians and their antagonists as well as by advocates and refuters alike. This work is a detailed investigation of how religious philosophy aligns with other worldviews and its potential reliability toward application and assistance in the development of a future relationship with ETI. The lens is focused on humankind's evolution of cognition, conjecture, logic, and knowledge about ETI as transformative toward these end points. As we know, the only way these end points can be resolved are through the eyes, experiences, and activities as undertaken by the only intelligent life-form of which we are aware-namely ourselves. Do you think your worldview about the meaning and purpose of life will be changed if and when ET comes calling?