A student asked why a revered elder teacher once said that whoever stands on the side of the Dhamma will be beset by Mara without letup.

Pra Ajarn explained that there are three natures: the wholesome, the unwholesome, and the neutral. The side of the Dhamma is the wholesome; the side of Mara is the unwholesome. The two are natural enemies, so whenever they meet, conflict is simply normal. The demeritorious side tends to bring suffering, its impurities creating problems and hardship, while the wholesome side tends to bring happiness, its purity resolving problems entirely. The two therefore cannot coexist.

The neutral side sits in the middle — taking neither side, and hostile to neither. It tends to pull people away from the wholesome side first, back toward the middle — for instance, during meditation, an inner voice might say, "That's enough, let's rest for now." Once someone has been pulled to the middle, the unwholesome then moves in to invite them further, toward unwholesome activities such as greed, aversion, delusion, or lust.

So, standing on the side of the Dhamma naturally means being harassed by the side of Mara — that's simply how it is. But refusing to stand with the wholesome out of fear of being harassed leaves one far worse off, since then nothing protects or looks after you at all. The unwholesome, once it has recruited someone to its side, tends to exploit them and then betray them once they're no longer useful — that is simply its nature. The neutral side, while it does no harm, likewise gives no real benefit — it merely leads one to waste time and resources on extravagance, until one is left with nothing, no time, and no vitality left, having gained nothing in return.

Pra Ajarn concluded that only the wholesome can truly help us. Even when old karmic results come due, if one still abides with the wholesome, it can turn something heavy into something light, and cause lighter matters to vanish altogether — and even at the moment of death, it leads one to a good destination.