How to handle bad-thoughts and ego-sense?

If ego-sense comes back upon you so strongly, it must be because something in you admits it. The Mother’s force is there always and can help you to get rid of these things, but you on your part must with faith and sincerity accept the Mother and put yourself entirely on her side so as to make it possible for the Force to work with effect. When bad thoughts come, you must reject them, not assent to them in your mind, not give voice to them in your speech, not believe in them or their suggestions. These things cannot vanish in a day, but if you do like that, they will diminish and lose their power to lay strong hold of you and disturb you, and in the end they will disappear.

Ref: The Mother with letters on The Mother