It is not the Mother who takes any test but the cosmic forces. If you read carefully She mentions the three kinds of forces that test us, – universal nature, adverse and hostile forces and, the spiritual forces. It does not mention that the Mother tests us.
She also mentions that these tests are arranged by these forces through people, events and circumstances. The Mother is there to help us go through them and come out with flying colours.
As to why these tests are allowed, it is to see our sincerity and readiness for the higher life. The purpose of these tests is not to judge and condemn or to reward and punish us. Their purpose is to prepare us. It is to see if our resolve is true and sincere, if our faith and surrender is complete or are we happy merely with lip service. What is being promised to us through the Yoga is the highest that man can envisage. Are we ready for that? Most of us, even in our relation with the Divine want only some material comforts and protection, we seek some selfish gains for ourselves and family. These forces come to remind us, pointing at the weak spots, the insincerities of our nature that claims one thing and acts in another way. If these tests or rather challenges were not there man we would be forever happy in our small comfort zones and never aspire to go beyond our present earthly state.
Affectionately,
Alok Da
