As a young priest he dealt with "late vocations" and, as Rector Major, launched the network of aspiring missionaries (the first erected in 1922 in Ivrea). During his Rectorate (1921-1931) the number of professed Salesians, after the horrors of the First World War, increased exponentially: from 4,638 Salesians and 437 novices in 1921 to 8,059 Salesians and 895 novices in 1931. He was distinguished by his missionary zeal. The 61st Salesian missionary expedition, in 1929, was the largest in Salesian history: 374 Salesians and 103 Daughters of Mary Help of Christians left.
He was responsible for the growth of the Salesian Family: he established the association of Past Pupils and founded the Secular Institute of Don Bosco's Volunteers (VDB). He consolidated the structure of the Salesian Cooperators and, through ADMA, promoted a strong devotion to Mary Help of Christians.
Even as Rector Major he was involved in the spiritual guidance of many, dedicating a lot of time to Confessions. His care for the interior life of the Salesians and the members of the Salesian Family made the great vocational and missionary movement possible. On the occasion of his feast day, the VDB shared some of the "Thoughts" of Blessed Philip Rinaldi, listed below:
- In recollection, in interior silence, the voice of God is heard, and the consecrated soul is formed.
- Do all possible good, according to the spirit of Don Bosco.
- Take care of the interior life; have a good spirit, without getting worried or worrying about success.
- Love the Lord and, in the love of the Lord, love your neighbour. It is the true carrying out of consecrated life.
- A deeply humble and meek person willingly gives self to others, sacrifices generously, loves Our Lord more perfectly.
- When we obey the arrangements that God has made for us, day by day, we do God's Will.
- Life is to work. The one who lives works; when one does nothing, one dies.
- Stay united together in the same spirit, and you will understand each other more easily.
- Kindness and Gentleness in looks, in the dealings, in words: conquer everyone with goodness.
- Jesus shed all his blood in obedience to the Father, and to save humanity. Jesus, our model, was obedient to the point of death, and death on the cross.
- We must not expect to do extraordinary things in matters of the spirit. Be simple like children.
- Piety is like food, and it is the first thing that is given to the creature. It is the food of Christian life, therefore we must not stop feeding it, so that the spiritual life does not fail in us.
- The essence of true piety is, Holy Communion, good works and, better still, the imitation of the one we want to honour: Mary Most Holy.