How do we know God's call is real?

The reality of God's call is discerned by the work of the Holy Spirit in a person's life. Unlike human-made doctrines or philosophical concepts, this call cannot be conjured from our efforts or understanding. Paul highlights that true knowledge of God comes from a divine revelation wherein the Holy Spirit enlightens our hearts and minds. It is a profound experience of bringing us from darkness to light and establishing a relationship with God that transcends mere intellectual assent or tradition.