'I heard the voice of the Lord saying, Whom shall I send?' Isaiah 6:8
When we speak of the call of God, we are apt to forget the most important feature, viz., the nature of the One Who calls. There is the call of the sea, the call of the mountains, the call of the great ice barriers, but these calls are only heard by the few. The call is the expression of the nature from which it comes, and we can only record the call if the same nature is in us. The call of God is the expression of God's nature, not of our nature. There are strands of the call of God providentially at work for us which we recognize and no one else does. It is the threading of God's voice to us in some particular matter, and it is no use consulting anyone else about it. We have to keep that profound relationship between our souls and God.
The call of God is not the echo of my nature; my affinities and personal temperament are not considered. As long as I consider my personal temperament and think about what I am fitted for, I shall never hear the call of God. But when I am brought into relationship with God, I am in the condition Isaiah was in. Isaiah's soul was so attuned to God by the tremendous crisis he had gone through that he recorded the call of God to his amazed soul. The majority of us have no ear for anything but ourselves, we cannot hear a thing God says. To be brought into the zone of the call of God is to be profoundly altered.