The Words of Sun Myung Moon from 1971
Who is a Saint?
A saint is different from a nationalist. A saint lives for the world. A saint is not someone whose loyalty is limited to one particular nation. Saints have appeared among people who are persecuted and chased away from their country. What this means is that saints appeared among people who are beyond the limitation of national boundaries and instead, strive for the world.
A saint is beyond any national or racial boundaries and toils and invests his life for the sake of the world. In so doing, he rejoices at persecution and ridicule, while living for the world with his conviction. He pioneers to find the ideal world by setting up a condition of risking his own life. He is not limited to the world, but goes beyond the world.
Reviewing all the saints in history, you will find that they are all the founders of religions. Jesus is a saint. Why? He said, "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life." (John 3:16) The prevailing idea of this teaching, is it about a man or God? It is all about God. Both Buddha of Buddhism and Mohamed of Islam are the same as well. They all pioneered the way as the founders of religions, while focusing on God as the center.
When you mention the four greatest saints in the world, you could not include Socrates as a saint. Socrates is the prince of knowledge. However, knowledge alone cannot occupy the life of human beings. God alone occupies and controls human life. Human life is the path through which people have tried to find the true value of life itself. It is not possible to find it by knowledge. You may gain your doctorate; however, if you consider that having the title itself is the ultimate value, it would be a grave mistake. Even though this world acknowledges your knowledge to be the highest, it cannot even compare to the life of a small child.
Religions appeared with authority that could control life, whereas philosophy was to pursue knowledge. Thus, Socrates could not be considered as a saint. Knowledge cannot resolve issues related to human life. You must know this fact.