Pacifism can be understood in various ways. In one way it is the refusal to engage in any violent or armed conflict. In this sense, it is a refusal to take part in a certain kind of battle. This sort of pacifism has little appeal and comes off as unrealistic at best and cowardly at worst.
But there is another understanding of pacifism: actively resisting evil in a nonviolent way. With this sort of pacifism one does engage in the battle, but paradoxically. Clearly, Jesus engaged in His final showdown with Satan in this manner. He refused to enter Satan’s world and use his tactics. Darkness cannot drive out darkness; only light can do that. Hatred cannot drive out hatred; only love can do that. Pride cannot drive out pride; only humility can do that. The Lord engaged in the battle and won the victory by being the Lord; He was victorious on His terms, not Satan’s.
There are certain people gifted to engage in battle in this way and we usually recognize their genius only later. We also revere soldiers and police of the more traditional sort, who at the risk of their own lives go forth to defend against the violent assaults of a dangerous foe. The point is to engage in the battle, to resist evil and stop its advance.
I have not seen the movie promoted in this trailer, but of all the trailers I have seen, this one does the best job of exemplifying the better understanding of pacifism: active resistance to evil.