"A cultural and intellectual movement of the Renaissance that emphasized secular concerns as a result of the rediscovery and study of the literature, art, and civilization of ancient Greece and Rome." - .
Individualism - http://www.dictionary.com/search?q=individualism .
"Belief in the primary importance of the individual and in the virtues of self-reliance and personal independence." - .
Secularism - http://www.dictionary.com/search?q=secularism.
"Religious skepticism or indifference." - .
Savonarola.
Savonarola was a friar and an alleged prophet who lived between 1452 and 1498. He preached dramatic sermons to the Florentines, telling them to repent and burn all their books (which were expensive and sought after during the Renaissance) in preparation for the judgment day. He believed these messages were sent to him from God, and it was his mission to tell the world. The Church did not approve of these teachings and ex-communicated him. Savonarola was challenged to walk through fire in order to prove he was God's messenger but refused. Because of this, he was arrested and tortured. He was forced to admit his messages weren't from God, and because of this "confession" he was burnt at the stake. This all relates to the themes of the Renaissance in that he disagreed with the Church (secularism), and was killed for it. This showed us the power and influence the Church had during this era, although it had much less power than it did in the Middle Ages.
Bottecelli.
Alessandro di Mariano Filipepi (who changed his name to Sandro Bottecelli) was born in 1446 and died in 1510. He painted pictures with both the themes of Classical Greece and Rome, and of Christianity. Before the Renaissance, art wasn't very common, but those pictures that were created were usually based on Christian ideas and stories. It is only during the Renaissance that we see the birth of paintings that involve myths from the Classical times.