In today's Gospel reading from Mark 8, Jesus rebukes Peter for thinking not as God does, but as human beings do. Obviously, we need to have the mind of Christ to think right. This again calls for union with God.
The tragedy of the world is that people do not see beyond their own immediate future or surroundings, and their thinking is basically self-centered . To think as God does, one must first look beyond this life and keep the overall picture in mind. The more we become united with Jesus, the more we'll be like him in every way.