Trust in a human (or general trust in the world) has no firm place in dogmatics or in theological ethics. Although it plays a crucial role in interpersonal relationships, it is a "homeless" concept theologically.
The Reformation newly emphasized belief in God as personal trust, and this recognition was later confirmed by the analysis of the respective terms in the Bible. However, the trust in man is discussed rather marginally, randomly and unsystematically in the theology.
The contradiction between the important role of trust in human life and its absence in the canon of theological themes signals a certain deficit of theology in the reflection of everyday human experience in the light of the Christian faith. The current crisis of trust calls for theological reflection.
Is trust in a human as such desirable at all? Is it not rather watchfulness what is important today? The trust in the world does not come from the inherent credibility of human. It results from the belief that, despite sin, we have not fallen out of God's hands and that Christ has overcome the powers of evil.
Trust is an ambivalent concept in the Bible. On the one hand, biblical authors warn against relying on man and his abilities, and they regard God as the only credible one.
On the other hand, Jesus invites for love and forgiveness, which certainly includes a renewal of trust, assures God's goodness bearing the world and justifies the trust in it. In a world infringed by human sin, an unlimited confidence cannot be proclaimed, but it is possible and necessary to build it patiently.
The article remains a sketch of a complex issue that would require more detailed discussion.