“I have studied, investigated, and listened to the Buddhadharma for a long, long time and I have not gained any benefit!” What benefit do you want? In fact, you have gained great benefit without knowing it. What kind of benefit have you gained?
When you study Buddhadharma here, you aren't out murdering people. Therefore, you are not among those murderers. Is that not a benefit? When you come here to attend Dharma lectures, you will not be found among thieves and burglars. If you don’t listen to lectures, you may get involved in theft, robbery, or even arson. Now that you study Buddhadharma, you are free from all these crimes. Wouldn’t you say that’s a benefit?
When learning Buddhadharma, you do not get involved in sexual misconduct. so you won’t commit crimes such as rape. You do many proper things so you will be free from all crimes. Isn’t that a benefit? When you study Buddhadharma, you won’t tell lies or go around cheating people. Then, you won’t commit the offense of lying. That is purifying your mouth karma. If you can go further to refrain from drinking, smoking, and taking drugs, then your mind karma would be purified too. Since you don’t consume those intoxicants, you wouldn’t be in the company of drug criminals either.
If purifying the three karmas is not a benefit of learning Buddhism, then what is it? If you don’t study the Buddhadharma, you may kill, or steal, or get involved in arson. Then the police will catch you and put you behind the bars, perhaps for life. Wouldn’t that be miserable? Since you are studying Buddhadharma, you are free from all these problems. If that is not a benefit, what is it then? Therefore, we should not grow weary of studying the Buddhadharma.