In my communication I shall examine the significations of the term πεῖρα, which can be encountered 20 times in the One Hundred Gnostic Chapters, being the key-notion in the closing considerations of four chapters (23, 24, 31, 32). The inherent intention is to show that Diadochus invests this word with an original use: it doesn't have the usual signification of test, trial, temptation, but designates the experience acquired on different stages of climbing onto the spiritual ladder. For Plato (The Republic, Gorgias) and Aristotle (Metaphysics), it was the term ἐμπειρία which designated the experience gained through the bodily senses, leading to a kind of knowledge acquired by practice. For Diadochus, on the contrary, πεῖρα comes to represent the experience acquired through spiritual senses. It leads to knowledge of the truth, involving the ability to discern between the causes of inner sensations, ability actualized by noetic illumination. This experience accompanies the pilgrimage of the human being towards the perfection of the resemblance to God and can become manifest as initial experience of faith (ch. 23), of immaterial sense (ch. 24), of discernment between the divine and the illusionary consolation (ch. 31, 32, 33), experience of the gnostic or of the theologian (ch. 72), experience of two desolations (ch. 87), experience of God's charity (ch. 91). The scope of my research includes also the analysis of the correlations between experience (πεῖρα) and charity (ἀγάπη), knowledge (γνῶσις) and illumination (φωτισμός).