However, of this much we must be sure. Never by our sole diligence or zeal nor by our most tireless efforts can we reach perfection. Human zeal is not enough to win the sublime rewards of blessedness. The Lord must be there to help us and to guide our hearts toward what is good. Every moment we must join in the prayer of David: ‘Direct my footsteps along Thy paths so that my feet do not move astray’ (Ps. 16:5) and ‘He has settled my feet on a rock and guided my footsteps’ (Ps. 39:3) – all this so that the invisible guide of the human spirit may direct back towards love of virtue our free will, which in its ignorance of the good and its obsession with passion is carried headlong into sin.

St. John Cassian