A reader made the connection between all is gift and all is grace, the famous phrase from the writings of St. Therese the Little Flower.
Tout est grace in Therese's writings point to three elements of her spirituality.
First, the entire dependence of a person on God. This is the relationship of the child to the Father, the trusting servant to Providence. Therese herself, as an anxious and nervous child, had to learn this, but because of her close relationship with her father, this became a reality in her relationship with God. Trusting brings an openness to God and gives a person great freedom.
Second, the idea of complete dependence on God led to an understanding of giving all to Jesus as His follower. Her response to her vocation to Carmel was an acceptance of the call of Christ to be a bride. One can see the movement of a person recognizing the Indwelling of the Trinity, having a relationship with God the Father, and then, Christ, His Son. The all is grace here is the complete trust of following Christ into the unknown.
Third, the unity of this saint with the Holy Spirit would bring a near completion of this conception of "all is grace". Through intense suffering and death of the ego, Therese went through the purification of the senses and spirit into the state of Illumination, moving very quickly into the state of Contemplation and Union. All is grace would describe one's entire life at that point.
Now, realize that one must work hard to get to these stages. Hard work which most people do not want to do....
Tout est grace.