7 What then of the two fears? There is a servile fear, and there is a clean [chaste] fear: there is the fear of suffering punishment, there is another fear of losing righteousness. That fear of suffering punishment is slavish. What great thing is it to fear punishment? The vilest slave and the cruelest robber do so. It is no great thing to fear punishment, but great it is to love righteousness. Has he, then, who loves righteousness no fear? Certainly he has; not of incurring of punishment, but of losing righteousness.
My brethren, assure yourselves of it, and draw your inference from that which you love. Some one of you is fond of money. Can I find any one, think you, who is not so? Yet from this very thing which he loves he may understand my meaning. He is afraid of loss: why is he so? Because he loves money. In the same measure that he loves money, is he afraid of losing it. So, then, some one is found to be a lover of righteousness, who at heart is much more afraid of its loss, who dreads more being stripped of his righteousness, than thou of your money.
This is the fear that is clean— this [the fear] that endures for ever. It is not this that love makes away with, or casts out, but rather embraces it, and keeps it with it, and possesses it as a companion. For we come to the Lord that we may see Him face to face. And there it is this pure fear that preserves us; for such a fear as that does not disturb, but reassure. The adulterous woman fears the coming of her husband, and the chaste one fears her husband's departure.
Source: Tractates on the Gospel of John (New Advent)