You can become a channel of profit for many

Venerable John Climacus ~ The Ladder of Divine Ascent
Step 12 ~ On Lying

¶5. When the demons see that, after the mischievous relater of jests has begun, we attempt to flee from hearing him, as it were from an infectious disease, then they try to catch us by two thoughts, suggesting to us: ‘Do not offend the story-teller,’ or: ‘Do not appear to love God more than they do.’ Be off! Do not dally, otherwise at the time of your prayer, the jokes will recur to your mind. And not only run, but even piously disconcert the bad company by offering for their general attention the thought of death and judgment. For perhaps it is better for you to be sprinkled with a few drops of vainglory, if only you can become a channel of profit for many.

Talkativeness is the throne of vainglory

Venerable John Climacus ~ The Ladder of Divine Ascent
Step 11 ~ On Talkativeness

¶2. Talkativeness is the throne of vainglory, on which it loves to show itself and make a display. Talkativeness is a sign of ignorance, a door to slander, an inducement to jesting, a servant of falsehood, the ruin of compunction, a creator and summoner of despondency, a precursor of sleep, the dissipation of recollection, the abolition of watchfulness, the cooling of ardour, the darkening of prayer.

Changed intention

Venerable John Climacus ~ The Ladder of Divine Ascent
Step 22 ~ On Vainglory

¶30. Often after being stripped by vainglory, we turn and strip it more cleverly. I have seen some who began spiritual activity out of vainglory, and although they made a bad start, yet the end proved praiseworthy, because they changed their intention.