Religious arguments are the last thing someone should engage in, if he’s looking to gain any worthwhile thing. Without making this too long, I'm going to explain the simple reason by which we take actions, why arguments is not just futile, but even backfires, and mention briefly on how our pious predecessors handled such.

In this world we have problems, and desires to have those problems removed, and the way we remove them is by taking action. Think hunger - eat, Poor – work for money, Fat - Exercise. So the thing that bridges us to our goal/action/wish/solution is the actions that we take.
Now, if you accept islam/believe that it is the true religion, then look and listen to the statements of our pious predecessors:
'I have never regretted an any as much as my regret over a day on which the sun sets and my life span decreases while my good deeds have not increased.' Abdullah Ibn Masood
A person who knows his lord should constantly be in the service of his Lord, because he recognizes and appreciates the value and importance of time; therefore during the day he observes his duties and fulfills the rights of the King [i.e. Allah], while his night is dedicated to conveying his love and devotion to his Lord; thus he never flnds a moment of repose. Ibn Qayyim

Some poor believers to the Prophet: "O Messenger of Allah, the affluent have made off with the rewards; they pray as we pray, they fast as we fast, and they give [much] in charity by virtue of their wealth."

So what are they doing by such actions? Simple, they have a problem, which is distance from Allah, and take actions that draws them closer to Him. In other words, they are worshiping Allah by drawing closer to him, by performing the actions that are beloved to Him, for people I reached by that which they love.
Think of two people, which of the two do you think is more beloved to their wife, the one that posts his wife’s pictures on social media and boasts about how beautiful she is, and how no one has such a beautiful wife, going at great lengths and details to describe her beauty. Or the one who tells his wife how much he loves her, and he appreciates her for whatever efforts she puts in, he buys gifts for her he tells her things she likes to hear, apologizes to her if he does wrong, and tells her how he's happy to be with her. Obvious isn't it, people are reached by what they love.
When you argue with it let's say a Christian, and you go as far as point out weaknesses in his religion, it doesn't matter whether it's true or false, what matters is how he feels. When you attack his religion, he feels offended, you attack him directly, he becomes more defensive, and the last thing he wants to do is to worship Allah and he might even go as far as attack the religion or attack Allah, so what benefit have you gotten from that? If the whole of Islam is drawing closer to Allah, do you think the Christian in any drew closer to Him, and how do you think the shaitan will feel about that? So why would you want to argue? Again, it didn't matter what was true or what was false, think of all the things we know that are good for us but we still don't do them, but whatever we feel or desire to do, even though we know it’s bad for us, we still do it. No one leaves his religion and enters into yours because it was attacked, no matter the religion.

Yes there might be a time to argue in situations where two people can talk together in order to reach and understanding, and wisdom is applied in speech. This is something that is quite hard to do and it's going to take a lot of time, it's not something that will be done with a comment or two, and you’re better of just taking actions that draw you closer to Allah.

What if others are the one attacking your religion? Here’s what Allah said:
And the slaves of the Most Beneficent (Allah) are those who walk on the earth in humility and sedateness, and when the foolish address them (with bad words) they reply back with salama

Ibn Kathir explains the Salama, that if ignorant people insult them with bad words they do not respond in kind but they forgive and overlook and say nothing but good words. In short, they can simply be ignored

This can go longer, but here’s the point; the no point behind religious arguments, especially the known ones people engage in. If you believe in Allah, then worship Him, and if someone believes otherwise, then their actions are for them, and ours for us, as Allah said:
"Whosoever does an evil deed, will not be requited except the like thereof, and whosoever does a righteous deed, whether male or female and is a true believer (in the Oneness of Allah), such will enter Paradise, where they will be provided therein (with all things in abundance) without limit. (Surah Ghafir 40:40)