Teacher of the prayer of the heart
Basil's lasting importance lies in his teaching on inner, noetic prayer. He instructed his disciples in obedience, humility, and the practice of the Jesus Prayer, and ordered the life of his sketes around daily reading of Scripture and the Fathers, watchfulness of the mind, fasting, and frequent communion. The sources relate that he had learned the discipline of inner prayer well before the printed Philokalia made such texts widely available.
He held that the writings of the Fathers were the key to a right reading of Scripture, calling the Scriptures themselves a saving medicine and warning that they must be approached through the mind of the Church. To this end he composed introductions to the works of Philokalic teachers such as Gregory of Sinai and Nilus of Sora on spiritual struggle and the prayer of the heart.