The four affirmations are these:
1 Tradition and family. The family is at the centre of Shinto and is seen as the main means of carrying on tradition, so most festivals etc are to do with family life.
2 The love of the natural world. Nature is seen as sacred, and the closer you are to the natural world the closer you are to the gods. There is a tradition of revering natural things as having a divine presence.
3 Cleanliness. This is a very important part of Shinto tradition. Taking a bath, keeping yourself and your environment clean etc take on the status of a religious ritual.
4 Matsuri. This word is hard to translate, but refers to the duty of worshipping the Shinto gods - the Kami. These gods, the stories surrounding them and the rituals associated with them are at the centre of the tradition. It is part of the tradition that the Emperor is descended from an ancestral goddess, which links the idea of religious faith and family tradition even more closely.
You can learn more about Shinto here.