Saint Aloysius Gonzaga entered the Society of Jesus to work for the conversion of heretics

 Saint Ignatius of Loyola founded 'The Society of Jesus', with the purpose of fighting against heresy and vice, apathy and decadence, under the banner of Christ.

Saint Ignatius of Loyola defeating the heretics.

Latin: Societas Iesu; abbreviated S.J.

We read in Saint Aloysius Gonzaga's  biography that he entered the company of Jesus to win souls for Christ:

During a painful kidney disease he devoted himself to prayer and reading from the "Lives of the Saints" collection by Surius.

Other books he read during that period of seclusion are, the India Letters, about the experiences of the Jesuit missionaries in that country, which gave him the idea of joining the Society of Jesus in order to work for the conversion of heretics and Compendium of the spiritual doctrine by Fray Luis de Granada. As a first step in his future missionary journey, he took advantage of his summer vacations at his home in Castiglione to teach catechism to poor local children.

                                

His goal in everything was the greater glory of God.

He had also read, in the Summa of Saint Thomas Aquinas, the Angelic Doctor, that those orders that have the highest rank are instituted to teach and preach and dedicate themselves to the salvation of souls.