When you turn on a light in a dark room, you won’t see a powerful chunk of blackness fighting off the light in the middle of the room – the darkness can’t decide it’s going to stay there. Why? Because there is no dark photon. It doesn’t exist on its own. Darkness is just the absence of light. So when light is present, darkness is absent. The same goes for goodness and truth. When there is one speck of good or truth, it has to outweigh the opposite, which is just the absence of goodness or truth.
As Anglo-Irish philosopher Edmund Burke said, “The only thing necessary for the triumph [of evil] is for good men to do nothing.” Because as it says in Acts, “If it be of God (Good, Truth, Love) ye cannot overthrow it.”
Evil is only the absence of good – can only be present when good is absent – just like darkness. And the only thing to combat darkness is light. You can’t fight darkness by using more powerful darkness to overthrow it.
No matter how small the idea of good or how small the idea of truth, it is worth expressing, because one is always greater than zero (or even a zillion zeros). Something is always greater than nothing.