Don Bosco chose as the motto for the Salesian Congregation, Da Mihi Animas Caetera Tolle, translated meaning, Give Me Souls, Take Away the Rest. This motto makes a very bold statement and demand of the Salesians. This essentially means that we are here to help in people's salvation. This is a huge, enormous, burdensome task. But to be fair, so was being crucified.
The Salesians are a tool of great importance in God's arsenal to combat Evil and the Devil. They play a key part, with the rest of the religious and priests of the Church in helping with the Sanctification of the Church. I think that Don Bosco chose Da Mihi Animas Caetera Tolle as his motto because it rings home a certain Mission. The Mission of the Salesians is to seek out those who are far from the Church, especially young people, and lead them to Christ.
On Don Bosco's feast day we can all remember to say a prayer to this beloved Patron of Young People so that the work of the Salesians, as well as the rest of the Church, can further the cause for holiness through the entire world!