The penitent St. Jerome.
Don’t give up hope. Don’t strive for mediocrity. Striving for mediocrity is a subtle way of telling God that you don’t believe in His gifts of grace or in his plan for you. Whatever your past may have been, you were created for holiness. You were made by God to become a saint. Don’t let the naysayers get you down. Strive for the holiness to which you were called at the moment of your baptism. It takes effort. It’s not easy. - Read the whole thing here.It is perhaps cliche, but 'a saint is a sinner who keeps trying'. A holy Carmelite told me that years ago.
We do not have to worry about merit or accomplishments to attract the merciful love of God. This is what St. Therese teaches and demonstrates in her little way of confidence and love. It is our misery which attracts the divine mercy. It is our sins and our faults which so attracts God that he sent his only Son to be crucified for our sins. Therefore, who cannot trust in merciful love when one is vulnerable enough, humble enough, to be embraced by it? The mystery is so deep, so wide, I can't express it. It seems to me the person who wrote to Fr. Z must be very pleasing to the Sacred Heart - to be so aware of his imperfections, and yet thirsting for holiness ...
“Do not be afraid of holiness, of letting yourself be loved and purified by God. … Let us allow God's holiness be transmitted to us. Every Christian is called to holiness; and holiness does not consist, first and foremost, in doing extraordinary things, but rather in letting God act. It is the encounter between our weakness and the strength of His grace”. - Pope Francis