You might ask: “Very well, Father! How do we achieve this purification? How do we drive all these logismoí away, now that they have entered our heart?“
By doing exactly that: ceaselessly calling upon the Divine Name inside our heart.
Of course, not only by that, but also along with the whole ascetic and therapeutic treatment “prescribed” by our Church, which includes: repentance (metanoia), fasting, wakefulness during the night (vigil), liturgical life (attending the Church services and, above all, the Divine Liturgy, partaking of the Holy Communion), and by maintaining the right dogmatic conscience (having the right belief and phronema, being orthodox).
For example, we cannot be a heretic (frequently called heterodox) and deliver a proper and fruitful noetic prayer.
If we do not keep the right beliefs about God, about the Holy Trinity, about Christ, we do nothing. An unbaptized or uninitiated, who deviated from the Orthodox Christian faith, may pray noetically as much as he/she wants; they will achieve nothing.
All these (the ascetic-therapeutic treatment of our Holy Church, combined with the right faith and our participation in the Holy Mysteries (sacraments)) lead to our purification from our sinful passions and the logismoí we have.
So, when our prayer descents into our heart, drives away all our logismoí, our heart is left pure, and hence the Holy Spirit enters. Then we experience the illumination, the second stage of our spiritual life, and this is when man becomes “a temple of the Holy Spirit”.