1. Paul Tillich, one of the most representative thinkers in the contemporary religion philosophy, is well known as a great master of contemporary theology.

2. Paul Tillich is a great thinker who made great contributions in both philosophy and theology.

3. A world-renowned philosopher in the twentieth century, Paul Tillich puts forward the concept of "ultimate concern", one of the most important in contemporary humanities.

4. Paul Tillich, a well known American existential theologian. He not only proposed 'Ultimate Concern', but also found out many unique theoretical viewpoints in the religious aesthetics.

5. So segregation is not only politically, economically, and sociologically unsound, but it is morally wrong and sinful. Paul Tillich has said that sin is separation.

6. From the existentialist perspective as defined by the theologian, Paul Tillich, the issue is one of courage.