The real reason for obstacles and difficulties

The illnesses you have are the signs of the resistance of your physical consciousness to the action of the Divine Power.

If you cannot advance in your sadhana, it is because you are divided and do not give yourself without reserve. You speak of surrendering everything to the Mother but you have not done even the one thing which she asked of you and which you have promised more than once. If after having called the action of the Divine Force, you allow other influences to prevail, how can you expect to be free from obstruction and difficulties?

Ref: The Mother with Letters on The Mother