As for this being revelation in the strict sense, the Church believes that revelation was complete with Jesus Christ. Revelations to mystics and/or other persons since that time are accepted as long as they are not contrary to what we have received from Scripture and tradition.

When devotions arise directly or indirectly from these private revelations, they can be approved as appropriate for use by Catholics. However, they are not usually imposed on the whole Church nor are they generally preached from the pulpit. Homilies focus on the Scripture readings for the particular Sunday or weekday and therefore, often speak of God's mercy and love but not necessarily the testimony of specific revelations.

Obviously, devotions to Jesus or Mary, under one form or another, are good as they reinforce Scripture and often renew already existing devotions. That seems to be the case with the particular devotion you mention.

It seems to me that the devotion to Divine Mercy bears some similarity to devotion to the Sacred Heart of Jesus which focuses on God's love for us. This devotion came about through revelations to St. Margaret Mary Alacoque in mid-17th century France. When the emphasis in Christianity seemed to be on God's severe judgment and humanity's utter worthlessness and inability to be loved by God, devotion to the Sacred Heart was needed to bring back the biblical image of God who is love.

In the same way, in an age when humanity was on the road to war and destruction (Faustina died in 1938), God's mercy needed to be brought to mind to combat hopelessness and despair for many who lived through such terrible sufferings. And there's no doubt that we continue to need to remember God's love and mercy all the time.

The fact that Sister Faustina was canonized is the Church's statement that she led a holy life and can serve as a model for us today. We can also pray to God through her intercession. Therefore, honouring St. Faustina is not only acceptable but desirable.

In the Middle Ages, feasts in abundance were established to honour Jesus and Mary under many and varied titles, as well as numerous saints to the point where it seemed there was hardly room to breathe.

With Vatican II, many of these were culled and the focus placed where it belonged, that is, on Sunday.

Sunday was the day observed by early Christians in honour of the Resurrection.

The early desert fathers and mothers would spend the week alone in their caves in prayer but on Saturday night they would gather in a central place and spend the entire night together in prayer and song, in sacred readings and celebrating the Eucharist.

On Sunday, they would have a festive meal together and then return to their respective solitary dwellings, nourished and strengthened in body and spirit. It was very inspiring to see in Turkey one of their dining rooms which survives to this day, as well as numerous cave churches where they worshipped.

That doesn't mean that we cannot keep certain feasts which inspire our lives. But apart from those remaining on the universal Church calendar, we are free to adopt the devotions which seem to suit our individual and community needs.

The feast of Divine Mercy on the second Sunday after Easter given by the pope when he canonized Faustina in 2000, it seems to me, is one such devotion.

Certainly, it is a very laudable devotion and not to be taken lightly for mercy is of the very essence of God.