In ordinary day-to-day arithmetic, three minus one is equal to two; but, in the arithmetic of the Atma the three (Ishvara-Jiva-Prakriti minus one (Prakriti) is equal to not two, but one (Ishvara) for, when the mirror (the Prakriti) goes, the image (Jiva) also disappears! When the mirror is eliminated, two entities disappear, the mirror and the reflection it can cast. And you merge in the Divine! (SSS Vol. 10, p. 34)
In the spiritual world, there is a different arithmetic, 3-1 = 1. There is you, the mirror, and the image. Remove the mirror, and there is only one left. Life is the mirror, body is the reflection. Be attached to God, and there is only One, God. (CWBSSB, p. 11)
Unlike in the case of ordinary arithmetic, 3–1 = 1 according to the spiritual arithmetic. You may argue that this equation is incorrect, but I firmly assert that it is correct. Why? Because it is based not on selfish worldly calculation but on selfless Atmic calculation, which aims at universal welfare. Of the three entities God, maya, and the Universe, God is the object, maya is the mirror, and the Universe is God’s reflection. If the mirror be removed, there will be no maya and Universe. Then only God remains. Therefore, 3–1 = 1. People are not in a position to understand such things because they lack the fifth type of knowledge viz. practical knowledge. (SSB 1990, p. 14)