Scripture as the 'soul' of theology continues to challenge both exegetes and theologians. I will address this issue mainly from a biblical perspective, to suggest how systematic theology can profit from its relationship with biblical studies. The reference text will be the Gospel according to John. In a brief overview, I will present the four passages in which what I call the 'paradigm of disappointment' is present: Joh 2:1-12; 4:46-54; 7:1-13; 11:154. The perspective of investigation will be narrative and rhetorical, highlighting the advantages of these approaches for the Christological and soteriological reflection developed by the evangelist. However, the narrative sequence and the rhetorical progression of these episodes finds its hermeneutical principle in Joh 1:12-13. This literary relationship poses a challenge from a historical-critical point of view: the Johannine prologue is a text most likely added later, in the concluding redactional phase. Therefore, the sequence of passages finds its narrative logic thanks to a later text that offers the hermeneutical criterion. These literary and methodological aspects will be explored to suggest some useful perspectives also for a systematic theology that stems 'from' Scripture: not only at the level of contents drawn from the Bible, but above all considering the narrative and rhetorical strategies chosen by the inspired writers to convey divine revelation, also in the different phases of the drafting of the texts themselves.