How to tolerate if someone insulting Buddhism? I first apologize to ask like this, I'm so sorry but I found people who don't respect other religions by my one older question I had to ask almost like this one that one I'm asking. As this religion is secular and against violence. Teaching kindness, forgiveness and beyond the concept of god and religion. But at the time when someone insulting Buddhism what to do ? In Buddha's time he was en lighted he could make them feel what they are doing, there were so many incidents he changed them but when I seen someone insulting Buddhism I feel like I must break first precept; all the time I tolerate because I'm not violent and it's not what I learn, but I get really really angry.
Also bad people look at us as beneficial sake and annoying that we are non-violence and so can't do nothing. There's quote of Napoleon Bonaparte “The world suffers a lot. Not because the violence of bad people. But because of the silence of the good people."
I don't expecting war and violence but peace. Thank you.
But at the time when someone insulting Buddhism what to do ?

I think you're supposed to remember that people are heir to their own karma.

If people insult Buddhism instead of respecting and learning from it, instead of benefiting from it, then you might feel pity for them (or preferably compassion).

I'm not sure you or I should see a need for forgiveness (i.e. a need for us to forgive them) because I (hypothetically) don't see their disrespect as hurtful towards "you" or "me". Perhaps you're identifying with Buddhism in some way (thinking that their disrespect is hurts others or hurts you, and needs forgiveness)?

I get really really angry.

See for example the Dhammapada, which 
begins with,


  
  "He abused me, he struck me, he overpowered me, he robbed me." Those who harbor such thoughts do not still their hatred.
  "He abused me, he struck me, he overpowered me, he robbed me." Those who do not harbor such thoughts still their hatred.
  Hatred is never appeased by hatred in this world. By non-hatred alone is hatred appeased. This is a law eternal.
  There are those who do not realize that one day we all must die. But those who do realize this settle their quarrels.
  


Getting really angry doesn't seem to me appropriate. I think of replying with anger as being like "putting out fire with gasoline", i.e. it may fuel disrespect and further anger, rather than putting it out.

I realize many people feel that they shouldn't usually get angry, but might feel that sometimes anger is excusable, normal, necessary, even praise-worthy, and inevitable (e.g. "if I get angry that their fault for being disrespectful, not my fault"); for example:


I don't usually get angry; but if you insult my mother then I'll punch you!
I wouldn't usually fight; if you attack my country then of course I will!
I'm usually a nice guy; but if you attack my religion then I can't stand it!


I also realize that some countries/societies criminalize disrespect, which might make it see normal to try to punish disrespect (e.g. by meeting it with anger), and/or to be averse to (and unaccustomed to) disrespect.

But ignoring what society does and looking at the scripture, remember the parable of the saw:


  Monks, even if bandits were to carve you up savagely, limb by limb, with a two-handled saw, he among you who let his heart get angered even at that would not be doing my bidding. Even then you should train yourselves: 'Our minds will be unaffected and we will say no evil words. We will remain sympathetic, with a mind of good will, and with no inner hate. We will keep pervading these people with an awareness imbued with good will and, beginning with them, we will keep pervading the all-encompassing world with an awareness imbued with good will — abundant, expansive, immeasurable, free from hostility, free from ill will.' That's how you should train yourselves.


because of the silence of the good people

If you think it might help, maybe you can disagree without getting angry.

If someone tells a lie about Buddhism, for example, maybe you can say what the truth is; or if it's not an appropriate place and time for a lecture, maybe say something short like "I disagree" or "I don't think so" ... enough so that if someone is interested then they can ask for more.

The world suffers a lot. Not because the violence of bad people. But because of the silence of the good people.

I think that Buddhism teaches that causes of suffering are ignorance, craving and attachment and so on.