Summary: On the 8th centenary of the birth of St. Clare of Assisi the author of this study rereads the letters of the Saint in the light of her leit-motiv: the religious life felt and experienced by St. Cla­re at San Damiano as a nuptial alliance sanctioned with Christ. The four letters to Agnes of Bo­hemia were conceived and elaborated on this biblical basis. The sole intention of Clare is to show to her distant spiritual daughter and sister that such truth is not only necessary and indispensable to the religious life, but also indicates tht only the nuptial alliance confirms and justifies the renun­ciation to human love, to the natural right of possessing material goods, and to the exercise of one's autonomy and liberty. All these things are donated to the one and only Lord, Jesus Christ, with whom every consecrated person is intimately united through a nuptial bond.