When I read the above passage in the Philokalia last night, it brought another quote to mind, so I'll post that one as well:
"On this account Paul says, 'Quench not the Spirit,' that is, the gift of grace, for it is his custom so to call the gift of the Spirit... The mouth is the door. Shut it, and fasten it, that it may both give light, and repel the attack from without. For instance, has any one insulted and reviled you? Do you shut the mouth; for if you open it, you add force to the wind. Do you not see in houses, when two doors stand directly opposite, and there is a strong wind, if you shut one, and there is no opposite draught, the wind has no power, but the greater part of its force is abated? So also now, there are two doors, thy mouth, and his who insults and affronts thee; if thou shuttest thy mouth, and dost not allow a draught on the other side, thou hast quenched the whole blast but if thou openest it, it will not be restrained. Let us not therefore quench it. " - Saint John Chrysostom, Homily 11 on First Thessalonians