For me, Michelangelo is the greatest artist in western culture. There are many of his works I could talk about, like the Sistine Chapel, his unfinished sculptures, David...But the Pietà in the Vatican and the Pietà Rondanini affect me the most.
He was 23 years old when he created his first Pietà! (Mercy or Pity). He created this masterpiece in a single block of marble! His skills were phenomenal! But there is more than technical skills! He shows so much maturity for then such a young man! Even though the Pietà was a common subject for Artists of the Renaissance, for him it had an additional meaning - his mother died when he was six years old. Despite his conflicts with the Catholic Church, Michelangelo was a devout Christian. The loss of his mother is never separated from his relationship with God during his life.
And this can be seen in his last work, the Pietà Rondanini. Mary is also holding Jesus, but not like the Pietà in the Vatican, where she is keeping him on her knees, but by being more subdued. She is placed behind Jesus, on top, looking like she is lifting him up. His mother was a gateway to God easily associated with Mary, making them one. His mother gave him birth, Mary takes his soul back home to God. (Michelangelo was looking for lightness in this sculpture). The Pietà in the Vatican is the only Artwork Michelangelo signed.