Feel-good rhetoric aside, your impact as an individual is limited and your defenses are fragile. In real terms, speaking out in even the most diplomatic way leads you to being aggressively silenced for not endorsing whatever the Sacred Infallible Truth may be in the time period that you live in, and there can be very severe consequences that impact your weakest link; your livelihood. The best you can feasibly do as an everyman is try with the people closest to you; the people that trust and respect you. Your partner, your family, your friends, your children. This is your only feasible option.
The issue with the passage you quoted ("And as for him who lacks the courage to defend even his own soul...") is that it's a call to arms yet it ignores the reality that you have no weapons with which to fight.
Reading between the lines of your post; if your society insists on going down a certain self-destructive path there's not much you can feasibly do other than watch it and hope your perspective is the misguided one.