Elder St Paisios on Instant Conversion…
he spiritual life does not require years. Within a second, one can find himself gone from hell into Paradise, if he repents. Man is changeable. He can become an angel and he can become a devil. What amazing power there is in repentance! It draws down divine Grace. A man can be saved if he brings one single humble thought to mind! But if he brings to mind a single proud thought and does not repent, and death overtakes him in this state, then he’s lost. The humble thought, of course, must be accompanied by an inner sigh, inner contrition. A thought is a thought, but there is also the heart. The hymnist reminds us, ‘With the whole soul and reason and heart?’ But I believe that the Abba here is referring to a more permanent state, and time is needed to attain to such a good state. For now, I make a mistake, I repent, I am forgiven at that moment; if I have a fighting spirit, I can gradually turn this temporary good state into a more permanent one, but until then I vacillate.
– ‘Spiritual Struggle’