If you desire to acquire the gifts of the Holy Spirit, first cleanse your heart of passions and the predispositions of sin, and make it a temple and dwelling place worthy of being inhabited by the Holy Spirit. How? Through inner attention and the return of the mind into the heart. Then practice sacred mental prayer in the heart, saying, “Lord Jesus Christ, Son of God, have mercy upon me.” When you prepare your heart, my beloved, then the all-holy, all-good, and most-manloving Spirit comes and dwells in you perceptibly, actively, manifestly.
Then, my brother, you will receive from the Holy Spirit whatever you long for. Do you love the gift of wisdom? You will receive it. Do you want to partake of the gift of the Apostles? You will acquire it. Do you aspire after the gift of martyrdom? You will receive it, if it is to your interest. Do you love joy? Do you love faith? Do you love love? Do you love the gifts of discernment, insight, foresight, foreknowledge, prophecy? The Holy Spirit will give you all these things.
~ St. Nicodemus the Hagiorite