|I'm sad again (unsplash.com)|
Every person alive wants happiness. Even common animals struggle to find happiness. But our karma/actions for the most part aren't in line with our wish. This is why we don't get to realize the happiness we want. It's simply because there's no truth to us. For example, when people come to the monastery -- to make offerings, observe precepts, or sit in meditation for the sake of praise or a good reputation, there's no real merit to what they're doing. They don't gain any real happiness from it. So they end up disappointed and dissatisfied (dukkha).
Then they start saying that making offerings, keeping precepts, and practicing meditation fail to yield good results. Instead of reflecting on the fact that they weren't right and honest in their intentions when doing these things, they say that there's no real good to the Buddha, Dharma, and Sangha (monastic community), that the Buddha's teachings are a lot of nonsense and lies. But actually the Buddha's teachings are an affair of the truth. If a person isn't true to the Buddha's teachings, the Buddha's teachings won't be true to that person -- and that person won't be able to know what the Buddha's true teachings are.