What is a truth of faith that cannot be fully understood or explained called?

In, Krsna, The Supreme Personality of Godhead, It's called Yogamaya, Lord Krishna plays like a ordinary living entity in his beloved pastimes as a cowherd boy but as the Supreme Godhead he puts up his curtain of Yogamaya. This makes Krishna enjoy more in loving exchanges with his advance devotees. who are simply in eternity, knowledge, and bliss serving the lord in their individual capacities.