I'm Jewish, and one of my favorite holidays is Purim.
I think that you should tell the Rabbi that there are some pretty strong laws and history behind Jews defending themselves by whatever means are necessary.
First (chronologically) is in the Exodus itself. In Exodus 13:18 it says:
But G-d led the people about, by the way of the wilderness by the Red Sea; and the children of Israel went up armed out of the land of Egypt.
[Emphasis added].
Second is Purim. Without the weapons to face the Persians intent upon killing them, Ahasueros' order to kill all of the Jews on (what is today celebrated as) Purim would have been carried out. Even if not fully successful, thousands or tens of thousands would have been murdered. The pre-emptive strike enabled by Ahasueros' 2nd order allowed our ancestors to survive.
Third is Chanukah: no (armed) revolt, no purified Temple or restoration of Jewish rule over our land.
The failure to fight to protect your life is a sin - G-d gave you the gift of life, and the failure to protect that life, and the good deeds and good influences that you have over others later on is a grave crime akin to suicide.
This is explained in the Talmud (this next part is directly copied from the website that follows it):
The Talmud repeatedly mandates self-defense against an attacker. For example, in Talmud Tractate Sanhedrin - which deals with Legal Judgments - the Rabbis explain Exodus 22:1, which states, "If a burglar is caught in the act of breaking in, and is struck and killed, it is not considered an act of murder." The next sentence explains, "However, if he robs in broad daylight, then it is an act of murder [to kill him]."
The first sentence clearly refers to a burglar who works at night. This burglar may be killed, presumably because he enters covertly, knowing that people could be present. He is deemed to have lethal intent. By contrast, the burglar who works by day - when people are normally around - presumably tries to avoid people in order to avoid confrontations, and so is not deemed likely to have lethal intent.
That quote is found at the following website, which not only explains this whole subject better than I can, but which I recommend that you peruse for yourself and have your Rabbi study it. Let's see what he says afterwards.
http://www.gunownersalliance.com/Rabbi_0029.htm
By the way, in the modern world when Israel was actually strong and willing to use that strength, none of its implacably hostile neighbors dared to, uh, fornicate with it. However, in the last 15-20 years, when Israel has shown little if any willingness to fight for itself (despite vast qualitative, quantitative and intelligence superiority), its neighbors and other enemies have mercilessly attacked it (i.e. its people, and usually the most helpless - just like Amalek attacked the rear of the Hebrews during the Exodus).
BTW, ask your Rabbi what is required for G-d to perform a miracle. If he says something like "be pious and pray a lot" he'd be dead wrong. Yes, you need to do those things, but you ALSO need to do everything possible to use the tools that G-d gave you to help yourself. G-d gave us a good mind (which many in recent history have thrown away on poisonous ideologies including modern liberalism), eyes that see, ears that hear, strong arms, etc. We also have money with which to buy actual tools, including guns and other weapons (and all of your money comes from G-d's beneficence to you). "G-d helps those who help themselves" not only makes sense, it is actually part of our theology (you can just sit around like a couch potato and expect G-d to give you a miracle Lotto ticket, or to save you when the Nazis are banging down your door, you have to DO something to even merit G-d's attention, let alone the miracle itself. This was the case at the Sea of Reeds (wrongly attributed to the Red Sea) when G-d split the waters for our ancestors.
While the great miracle of the splitting of the Red Sea is well-documented, many people are not aware of the important factor which was needed for this event to take place. Hashem was unwilling to perform this awesome miracle until He saw man's willingness to exhibit faith in Him. Therefore, it was not until Nachshon the son of Aminadav of the tribe of Yehudah bravely jumped into the water, showing unbelievable faith in Hashem, that the sea actually parted.
http://www.tfdixie.com/parshat/beshalach/011.htm
In other words, without actions intended to help your situation yourself, G-d won't help you. Putting this in the context of defense against a criminal or a genocidal regime, merely praying for G-d's help will do you no good - you must use the tools that G-d gave you (including weapons) to help yourself first. Your Rabbi won't be able to dispute this without showing that he doesn't believe in the Torah. If that's the case, find a new Rabbi.
Needless to say, I'm a Jew with guns. As the correct version of the saying goes, "Never Again - but if again, then not for free."
