One of the ancient chants assigned even to this day to Good Friday are what are known by the Latin title Improperia. By our best estimate it appeared in the Liturgy in the 8th century and became a standard part of the Roman Rite in the 14th.
It quotes today's first reading from the Prophet Micah, "O my people, what have I done to you, or how have I wearied you? Answer me!" If we listen to the present liturgical text without the biblical text in mind, it can sound as if it's purpose is simply to make us feel guilty by telling us what good God has done for us and how shabbily we treated Jesus.
If, however, we read the rest of today's first reading we find out that the goal is not to make us feel guilt the goal is something else.
Will the LORD be pleased with thousands of rams, with myriad streams of oil?
Shall I give my first-born for my crime, the fruit of my body for the sin of my soul?
You have been told, O man, what is good,and what the LORD requires of you:
Only to do the right and to love goodness,
and to walk humbly with your God.
Three simple things:
Walk humbly with your God
Even when we treated Jesus poorly, he responded with love. What God wants is not sacrifices or feelings of guilt for their own sake, but change of behavior.
It strikes me that the last of the three is the key to the other two. If I can concentrate on walking humbly with God all day long, the others will fall more easily into place.