My faith gives me great comfort.
My pants give me great comfort, but I'm not going to make supernatural claims based on that fact, and at least they definitely exist. In the words of Sam Harris, "before we examine the validity of this claim, it's worth noting that it's a total non-sequitur"; the amount of comfort or sense of wellbeing afforded someone by a given article of faith has no relevance on the truth-value of that claim. This type of logical fallacy is called argumentum as consequentum : Appeal to Consequences or wishful thinking. Sam gives the example of his imaginary belief that there is a giant diamond buried in his back-yard. He states that he would be laughed at and thought a lunatic if he started making statements like “It gives me an enormous sense of wellbeing to believe that there is an enormous diamond buried in my back yard.”, “I wouldn’t want to live in a world where there wasn’t an enormous diamond buried in my back yard, it gives my life meaning.” None of these statements give us any inclination to take the existence of such a gem seriously, yet somehow we are expected to refrain from laughing hysterically when the faithful use these kinds of phrases about their equally unfounded claims. If there is a reason we ought not to laugh it is not that we should respect faith, but that what they are really saying is “Please stop highlighting my misconceptions, it hurts.” We should be sympathetic to this since it will not help us free them from their delusion if we inflict unnecessary discomfort, but this should not signal an end to the discussion. Sometimes a little pain is necessary for progress.
Having established that the truth of the statement “My faith gives me great comfort” has no bearing on whether the object of faith is true, let’s have a look at the premise itself. Well clearly it is in many cases, people do derive comfort from the ideas that they will never die, and neither will their beloved friends and family, that all will live in bliss in paradise for eternity, that their prayers for their loved ones and the world at large are having some positive impact etc. Unfortunately, given the lack of evidence for these suppositions, their positive affect on mental state is nothing more than the placebo effect in action. Additionally, I hypothesize that to a large degree the need for this comfort is brought about only because of the pre-existence of the faith. Like the smoker for whom a cigarette buys temporary respite from the pangs of withdrawal that would not be present were he not a smoker, much of the distress people of faith find themselves in need of alleviation from is brought about by having been taught falsehoods such as that they are born in sin for which they must atone, or that they or their loved ones will go to hell for failing to believe (the argument ad baculum : appeal to force). People are taught to feel guilt for harmless actions, often perfectly natural, sometimes even biologically unavoidable ones. This guilt can only be assuaged by prayer, or confession, or other such wastes of effort that could otherwise be used doing something genuinely beneficial. The Catholic Church even used to allow people to pay cash to buy-off their sins with cash to make themselves feel better; these days many churches ask their congregations to pay tithes for the same reason.
Even if it is true that faith gives comfort, it's worth noting that taking morphine or laudanum would probably make you feel much more relaxed about your place in the world too, but I don't think anyone sensible is going to advocate that as a viable long term solution.
In addition to all this, the argument that you have a right to something or that it is beneficial to mankind because it brings you personal comfort is not good enough. Giving support to organisations that do evil deeds or preach that they should be done, because it makes you feel better is clearly an immoral act, and should be discouraged whenever possible. After all, we would not listen politely to people who say “I like punching people in the face, it makes me feel better about myself and my place in the world.” Or maybe we would, but only out of fear that they may punch us in the face.