The Apostle Paul writes in the First Epistle to the Church of the Corinthians a series of exhortations about the Christian life due to the divisions inside the community, among which he dedicates one to the apostolic magisterium and teaches: "we are co-workers in God's service; you are God's field, God's building. By the grace God has given me. I laid a foundation as a wise builder and someone else is building on it. But each one should build with care."
Being co-workers means to work progressively, with continuously improving, to solve problems that affect the common good. Paul makes the analogy with the architect who builds. Being cooperative with God means cooperating with the Divine Providence.
Thomas Aquinas tells us that God is the source of all the perfections we see in the creation and this perfections are called spiritual gifts. In the universe there are different degrees of perfection. The meaning of life is to improve the perfection, the order of the universe and it is this idea that gives rise to the concept of continuous improvement, the Spiritual Gift of Fortitude.
It is here where we understand in essence what is the spirit, the soul is the perfection of the body and the spirit is the divine substance as Thomas Aquinas explains, but more precisely the spirit is the ability to improve, to uplift, to build like the good architect.
The progressive work is in the Christian faith one of the 7 gifts of the Holy Spirit.
When we live the gift of fortitude, that is when we continuously improve we are cooperators with God in his plan, we are co-workers with the Beatitudes, we act with progressive mentality. Continuously improvement means having a life plan, it is to approache gradually to the same perfection of God. We are called to the conformity with God through the spiritual gift of fortitude, the progressive work.