Being a Saint starts with baptism, in the name of the Father and of the Son and of the Holy Spirit.
There, at the very beginning, is the centre of the Communion which the saints belong to.
We are Saints because of what we are, rather than what we do. What we are, comes from the sacraments, in which we become Sons (and Daughters).
Our relationship with God, or rather God's relationship with us, is what sanctifies us. It is what grows from this relationship which sanctifies us or makes us Saintly.