Gurdjieff makes it clear what, in his view, is the purpose of human life and, more importantly, what its ultimate aim should be - that can be simply formulated as...to develop a Soul in order to become a conscious and creative servant of God's Work.
This service can be rendered during life and after death. To reduce the aim to anything less is to diminish its power to enable this transformation, and yet, one must be very much on guard to not allow it to become fantasy. Soul creation is first and foremost, practical.
The apex of work on oneself is to develop the ability to serve - it is not the beginning, as we are simply incapable of truly serving. Hence, Gurdjieff's insistence on first becoming an outright 'egoist' before one can become an outright 'altruist'.
The Gurdjieff Work is a Mystical Way in the midst of life as it seeks, step by step, to develop an inner vehicle that is capable of communion ('communicating') and union ('joining') with God. It is also a Transformational Way as that process of communion (and union), to the degree that it is attained, enables an organic action to take place that has practical consequences. The Work, then, is a two-way street: our way to God is also God's way to us.
The allusion to create a Soul is scattered through the Gospels in almost every parable and calling to attain 'everlasting life'. The directive is to follow the first great and second commandments of Christ that is to "love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind...and... love thy neighbour as thyself." (Matthew 22:37-40 KJV).
Spiritual work passes through various stages of 'serving' - that is, Self-Serving (or Work on Oneself for one's own benefit), Other-Serving (or Work with Others for their benefit), Work-Serving (Work for the Work), and God-Serving (Work for Everything). Such is the great purpose of human life.
For what shall it profit a man, if he shall gain the whole world, and lose his own soul? Mark 8:36 KJV.