Self denial is a spiritual discipline. Self denial allows us to put our ego in check and push back against a world of self importance and a sense of entitlement. When we are able to practice self denial we are intentionally working to put ourselves in right relationship with God and with others. We are not the center of the universe. Jesus was clear that we are designed for relationship and thriving and healthy relationships require a self perspective that is not over inflated.
Mark 8:34, Romans 7:15-20