Do Not Engage With Them
Don't start an argument with any religious hardliner, not for the fear of fierce opposition but to avoid wastage of your precious time. 'You cannot teach them anything.' They will continue to believe that their ho!y book is the only one to be worshiped and followed!
Very few of the them, the highly learned and rational ones, realize the need for reforms in their religion. But they too have to glorify their religious book! They can't speak against the majority. Very rarely they speak against militancy. Very rarely someone from that lot speaks the truth. Respect such true heroes.
Only those who spit venom against other religions become popular in Jihādī brotherhood/s. So a lot of them, little educated and militant minded write inflammatory and abusive things about other religions. If you read/hear a lot of what they have written/spoken (in leaflets, gatherings, blogs, forums, rallies etc.) about your religion, you will feel that you need to correct them. Please believe me - 'You cannot teach them anything.' Only states and courts can correct them! So whenever you find any such text or speech just immediately stop reading/listening to it. If you can complain or report abuse, please do so.
They will entice you in different ways to engage with them, don't oblige. If you are in their neighborhood, be prepared to avert a physical assault; inform authorities/courts and your people, stay healthy and physically fit. Sometimes they will start or pose as moderates, but at critical junctures they will take a harder stance.
Some of them, talk sweet to woo innocent girls of other religions/sects, while treating their wives and sisters as inferior beings. Some of them, secretly enjoy deaths of people of other communities, sects and religions. They want to keep as many wives as possible and then father as many children as possible. This is their strategy to increase their brute force. This population eats into the resources of secular countries like India. They remain poor because of this strategy and then point fingers at wealthier communities.
Remain calm even after reading all this. Let us hope that powerful states/armies and international secular courts will punish them.
No Need to Defend Our Religious Texts
You don't have to defend any of the ancient Hinđū texts. Even if there are some imperfect verses, these texts as a whole are far better (and older) than texts of other religions. In all the ancient religious books, there are some inconsistent philosophies, we have to accept it as history! Most of the educated Hinđū/s are progressive and don't only look back for knowledge and wisdom. Hinđūism means freedom. Enjoy it. You don't have to follow anybody!
We should not glorify Veđa/s (even if there are so many great verses/श्लोक). At the same time we should not remain in the company of those who criticize these ancient Hinđū texts and glorify texts of other religion/s. Boycott such people; always.
Some Indian politicians (currently out of power in the center) seek the company of treacherous leaders of militant minded communities during elections. Never vote for these selfish cowards, even if they are Hinđū/s. Some Hinđū moderates tolerate fundamentalists of other religions a lot; And to prove that they are 'secular', keep criticizing average religious minded Hinđū/s. These moderates and liberals don't have a sense of proportion. We don't have to even laugh at them; look over or move away without irritating them. Let them remain with the company they deserve. Let us have space and acquire knowledge for peace (shānti)!