More valuable than any proof for the existence of God demonstrated in books is a personal experience of God. People of prayer and interiority know God mainly through God’s working in their lives. They have known God in the prayers that were answered, in problems and in difficulties overcome that only the power of God’s Spirit can explain, and above all in the charity of their lives that transcends human patience and love and reaches a level of selflessness that faith alone makes possible. The witness of a selfless God-centered life, therefore, is the greatest proof of the existence of God. People find God in people who have already found God and live in that love.