Oneness is Truth

Swami Vivekananda says :

To be able to use what we call Viveka (discrimination), to learn how in every moment of our lives, in every one of our actions, to discriminate between what is right and wrong, true and false, we shall have to know the test of truth, which is purity, oneness. Everything that makes for Oneness is truth. Love is truth, and hatred is false, because hatred makes for multiplicity. It is hatred that separates man from man; therefore it is wrong and false. It is a disintegrating power; it separates and destroys.

Love binds, love makes for that oneness. You become one, the mother with the child, families with the city, the whole world becomes one with the animals. For love is Existence, God Himself; and all this is the manifestation of that One Love, more or less expressed. The difference is only in degree, but it is the manifestation of that One Love throughout.

Therefore in all our actions we have to judge whether it is making for diversity or for oneness. If for diversity we have to give it up, but if it makes for oneness we are sure it is good. So with our thoughts; we have to decide whether they make for disintegration, multiplicity, or for oneness, binding soul to soul and bringing one influence to bear. If they do this, we will take them up, and if not, we will throw them off as criminal. (II, 304 - 305)