Devotee is he who is very compassionate to these conditioned soul. Kṛpā-sindhubhya eva ca. Kṛpā means mercy, and sindhu means ocean. A devotee is ocean of mercy. He wants to distribute the mercy.
Just like Lord Jesus Christ—he was God conscious, Kṛṣṇa conscious, but he was not satisfied in himself. If he would have continued his God consciousness alone, he would not have met crucification. But no. He want to take care of others also, the others should be God conscious, others should be Kṛṣṇa conscious. He was forbidden by the king not to do that. So at the risk of his life he did it. That is the nature of devotee.
Therefore the preacher devotee is the most dearest devotee of Lord. That is stated in the Bhagavad-gītā. They are going outside, they are preaching, they are meeting opposing elements. Sometimes they are defeated, sometimes disappointed, sometimes able to convince; there are different kinds of people. So, not that every devotee is very well equipped. There are three classes of devotees also. But that endeavor that, "I shall go and preach Kṛṣṇa consciousness," is the best service to the Lord, because they are trying in opposition to elevate people to the highest standard of self-realization.