He for whom no one is put into difficulty and who is not disturbed by anxiety, who is steady in happiness and distress, is very dear to Me.
A few of a devotee's qualifications are further being described. No one is put into difficulty, anxiety, fearfulness, or dissatisfaction by such a devotee. Since a devotee is kind to everyone, he does not act in such a way to put others into anxiety. At the same time, if others try to put a devotee into anxiety, he is not disturbed. It is by the grace of the Lord that he is so practiced that he is not disturbed by any outward disturbance. Actually because a devotee is always engrossed in Kṛṣṇa consciousness and engaged in devotional service, all such material circumstances cannot woo him. Generally a materialistic person becomes very happy when there is something for his sense gratification and his body, but when he sees that others have something for their sense gratification and he hasn't, he is sorry and envious. When he is expecting some retaliation from an enemy, he is in a state of fear, and when he cannot successfully execute something he becomes dejected. But a devotee is always transcendental to all these disturbances; therefore he is very dear to Kṛṣṇa.
(Bhagavad-gītā As It Is 12.15, Translation and Purport)