Duality, partnership, and the dance between opposites. Two creates relationship β without 2, there is no reflection, no other, no love.
Duality: light/dark, masculine/feminine, heaven/earth. In Pythagorean tradition, 2 is the first female number β receptive, reflective, balanced.
Yin β the complementary to yang. Two is considered lucky because "good things come in pairs." Associated with earth and harmony.
Beth β house, container. Chokhmah (Wisdom) and Binah (Understanding) form the divine pair. The duality of creation itself.
Dvaita β duality of Atman and Brahman in non-Advaita traditions. Ardhanarisvara: Shiva and Shakti as one. The moon's number.
The Two Truths: relative and absolute reality. Also the two aspects of the path: wisdom (prajna) and compassion (karuna).
In Islamic symbolism, 2 represents the two main sources of guidance: the Quran and Hadith. The two holy mosques of Mecca and Medina.
Generally positive worldwide; Chinese culture particularly favors 2 for its association with harmony and pairs.