The word "penitent" means feeling sorry or regretful for something wrong that you have done and being willing to change or make amends for it. Full definition
We can look to him and accept as penitent sinners his going to death for us. (religion-online.org)
There are profound insights into the priestly mercy of the Sacred Heart viewed from the perspective of the dying Penitent Thief. (faith.org.uk)
Prayer for the Day: «O God, whose glory it is always to have mercy: Be gracious to all who have gone astray from your ways, and bring them again with penitent hearts and steadfast faith to embrace and hold fast the unchangeable truth of your Word, Jesus Christ your Son; who with you and the Holy Spirit lives and reigns, one God, for ever and ever. (rachelheldevans.com)