Today, this of all days in the liturgical year, is the time to remind our selves it was our sins which put Christ upon the Cross--Original Sin, the sins of humanity, and our individual sins. Today's first reading (Isaiah 52:13-53:12) makes that all too clear. "With true sorrow for my sins and a firm resolve to amend them", Lent, Holy Week, and the Triduum gives us the opportunity to focus on the relevant words of the Confiteor.
In some places, during the veneration of the Cross at the Good Friday service the choir sings The Reproaches of Christ (Improperia). Aristotle A. Esguerra, who 'blogs at Confessions of a Recovering Choir Director, has a post with the complete text. In the comment box, there is this link (PDF format) to a term paper written by the 'blogmaster of Old Oligarch's Painted Stoa which explains the origins and meaning of the text.
Sobering reflection is the order of the day.