In this article intertextuality is introduced as one important part of a theory of the semiotics of biblical texts. Intertextuality is an essential factor for the generation of the meanings of a text in the acts of the production and reception of a text. It opens the internal structure of a text with regard to its relations to other texts. The semiotic concept of intertextuality distinguishes three ways of intertextual readings: production-oriented intertextuality, reception-oriented intertextuality and experimental intertextuality. This wide but differentiated concept of intertextuality can serve as a theory and helpful method for investigations of the history of biblical texts as well as for reflected school lessons, sermons and poetics in today’s times. An intertextual reading of the first chapter of Matthew provides a test case of this semiotic concept of intertextuality.