“God, who deigned to redeem the human race through the precious blood of Thy only-begotten Son, Our Lord Jesus Christ, graciously grant that whoever approaches to adore the life-giving cross, may be freed from the bonds of their sins.” [My translation] The Sarum Missal, Ed. J. Wickham Legg, (Oxford: Clarendon, 1916), p. 320.
This is the collect recorded in one of the more famous medieval liturgies. By the twelfth century the feast for the Exaltation of the Cross was a well-established date on the liturgical calendar. Numerous medieval sermon collections contain homilies for this feast. Here is one example from the early twelfth century:
“This Holy Cross should be venerated by angels and adored by human beings. Certainly, through the Cross the devil was taken captive, the world was freed, and hell plundered, [while] paradise rejoiced. All Christian people throughout the world have been invited to the heavenly kingdom. The celestial homeland exults over the triumph of the Cross, the Church rejoices, [while] the Jewish perfidy falls apart. Death is laid low by the victory of the Holy Cross….the Holy Cross has become for us the key to heaven [and] the powerful destruction of hell.” [My translation] Honorius Augustodunensis, De exaltatione sanctae crucis [On the Exaltation of the Holy Cross], Patrologia Latina 172: 1001-02.