Divine Providence entrusted a very important role in Saint Faustina's mission to her confessor and spiritual director Fr. Michael Sopocko.
During Saint Faustina's stay in Vilnius (Lithuania) in the years 1933-1936, he was for her an irreplaceable help in discerning interior inspirations and visions.
Obedient to his orders, she wrote a DIARY, which is an now an extraordinarily valuable document of Catholic mysticism. In the DIARY one can also find evidence of Fr. Michael Sopocko's extraordinary character and his work in fulfilling the desires of the Lord Jesus.