Dear Parishioners and Friends of St. Mary’s of the Lake:
(Below is Part 2 of Pope Francis’ catechesis on the Holy Mass on Jan 3, 2018 at the weekly Audience at St. Peter’s Square): 

 ⬥ The words we say with our mouth are accompanied by the gesture of striking our breast, acknowledging that I have sinned through my own fault and not that of others. Indeed, it often happens that, out of fear or shame, we point a finger to blame others. It costs us to admit being at fault, but it does us good to confess it sincerely. Confess your own sins. I remember an anecdote that an elderly missionary used to tell, of a woman who went to confession and started speaking about her husband’s failings. Then she moved on to talk about her mother-in-law’s failings and then the sins of her neighbors. At a certain point, the confessor said to her: ‘But, madam, tell me: have you finished?  --Very well: you have finished with the sins of others. Now start telling your own’. Tell your own sins!
After the confession of sins, we ask the Blessed Virgin Mary, the Angels and Saints to pray to the Lord for us. In this too, the communion of Saints is valuable: that is, the intercession of these ‘companions and life examples’ (cf. Preface of 1 November) supports us on the journey toward full communion with God, when sin will be abolished once and for all.
In addition to ‘I confess’, the Penitential Act can be performed with other formulae, for example: ‘Have mercy upon us, O Lord, / for we have sinned against thee. / Show us thy mercy, O Lord, / and grant us thy salvation’ (cf. Ps 123:3; Jer 14:20; Ps 85:8). Especially on Sundays, the blessing and sprinkling of water may be performed as a reminder of Baptism (cf. General Instruction of the Roman Missal, 51), which washes away all sins. It is also possible, as part of the Penitential Act, to sing the Kyrie eleison: with the ancient Greek expression, we praise the Lord –Kyrios-- and implore His mercy (ibid., 52).
⬥   Sacred Scripture offers us luminous examples of ‘penitent’ figures who, coming back into themselves after having committed sin, find the courage to take off the mask and open themselves to the grace that renews the heart. Let us think of King David and the words attributed to him in the Psalm: ‘Have mercy on me, O God, according to thy steadfast love; according to thy abundant mercy blot out my iniquity’ (cf. 51:1-2). Let us consider the prodigal son who returns to the father: ‘God, be merciful to me a sinner’ (Lk 18:13). Let us also think of Saint Peter, of Zacchaeus, of the Samaritan woman. Measuring ourselves with the fragility of the clay of which we are molded is an experience that strengthens us: as it makes us take account of our weakness, it opens our heart to invoke the divine mercy which transforms and converts. And this is what we do in the Penitential Act at the beginning of Mass.