Can gun control advocates point me to the guarantee that government will always be there to protect me?

I'm not sure leftists who don't want citizens to own guns realize the quid pro quo, namely that in return government will always be there to protect us. So, would a leftist be so kind as to provide me with an example of such a guarantee from government? I'm not picky about the level of government (city, state, county, federal, town), I just want to see how the guarantee reads. Thanks.