Cape Town - It's Archbishop Emeritus Desmond Tutu at his best.With just a few lines, he has taken the virtual world by storm.In a letter addressed to a newborn on the other side of the world, Tutu writes to his "little sister" after her father apparently wrote to him wanting to compile a book of letters for his daughter.The Arch, who refers to himself in the letter as "a very old grandfather from SA", wrote that while he was reaching the end of his journey on earth, Juliet's was just beginning."We may never meet on earth, so I thought to send you a secret. Well, it's not really a secret because we should all know it. So I don't mind if you tell everyone else," he said."Did you know that all people belong to one family, the human family? That although we may look nothing like each other, live in separate homes, practice our own cultures, subscribe to different religions – and some of us have more money than others – we are all sisters and brothers of God's family?"'This is what the world needs'He concludes his letter, dated July 2016, with words of wisdom for little Juliet."You and I, and everyone else, were born with the same purpose: for love, for goodness and for one another."The Desmond and Leah Tutu Foundation has since confirmed the letter's authenticity. It has gone viral on social media.A US woman earlier this month posted the letter on Facebook, explaining that Juliet's father was a colleague."This. This is what the world needs," she said."Not only did he respond, but he wrote what the world must embrace. This is beyond beautiful. Please share. The world needs to see this."It has been shared almost 2 400 times.Attempts to reach the Facebook user have been unsuccessful.