Devotee means one who accepts the supremacy of the Supreme Lord, and he is convinced, his eternal relationship with God.
Just like Lord Jesus Christ. He was threatened with death punishment. He was crucified. Still, he was convinced, his relationship with God. Here is a devotee, example of devotee. Devotee means he is firmly convinced about his relationship with God. And what is that relationship? That relationship is on the basis of love. The devotee loves God, and God loves devotee. This is the only relationship. That's all. God is after devotee, and devotee after God. This is relationship.
So one has to establish this relationship. Just like Arjuna is in relationship with Kṛṣṇa as a friend, similarly, you can be in relationship with God as a lover. You can be in relationship with God as master and servant. You can be in relationship with God as father and son. There are so many relationships. As we have got relationship within this material world, this is only perverted reflection of that five relationship with God. But we have forgotten that. This Kṛṣṇa consciousness movement is to revive that consciousness. It is nothing new. To forget God means that is abnormal condition, and to have relationship with God is normal condition. So Kṛṣṇa consciousness means to be reestablished in our normal condition of life.