The Son of God became human to reveal God to us. During his life on earth, Jesus taught his disciples in parables; he worked miracles which were signs of God’s power; and he taught them by his whole way of life. But at the Last Supper, preparing to face death, Jesus knows that his disciples have not yet fully grasped the truth that he is teaching them. The Holy Spirit, who comes at Pentecost, will lead them into the fullness of the truth. And the truth is that at the heart of God is loving relationship: three Persons, Father, Son and Spirit, living in mutual love and self-giving. This truth is a mystery that is beyond human understanding, even with the help of divine grace. Like some of the other great truths that we encounter in our lives – the wonders of nature, the mystery of a person we love – the Trinity is not a problem to be solved, but a truth to be encountered, accepted and lived.