From Metropolitan Anthony Bloom:
There is always a cost to discipleship because, from start to finish, it means a gradual overcoming of all that is self in order to grow into communion with that which is greater than self and which will ultimately displace self, conquer the ground and become the totality of life.
And there is always a moment in the experience of discipleship when fear comes upon the disciple, for he sees at a certain moment that death is looming, the death that his self must face. Later on it will no longer be death, it will be a life greater than his own, but every disciple will have to die first before he comes back to life. This requires determination, courage, faith.