The article interprets Tillich's varied elaborations on different aspects of eros, mainly in his Systematic Theology, by reading them in the light of Jean-Luc Marion's phenomenological description of eros in its various aspects in The Erotic Phenomenon. The erotic in Tillich not only has to do with sex and desire, but also with his commitment to a realistic approach to what it means to be human, to human culture, and to confronting false and estranging interpretations of basic human phenomena. What seems to be missing in Tillich, however, is a more comprehensive treatment of eros/desire that would make possible an understanding of the phenomenological (and consequently existential) fullness of this phenomenon. I suggest that this can be achieved by reading Tillich by way of Marion's phenomenological analysis. This also has the virtue of overcoming the all-too abstract character of Tillich's reasoning without at the same time dismissing Tillich's treatment of eros. I will also draw out some implications for how one might deal with eros and desire in the emerging discussion in present systematic theology.