The thought, here, is that accidental man (man as he develops over time & "thinks" himself to be, his "I") is actually a composite of contingent and luck-based qualities, until he achieves his possible destiny, which is to be reborn anew by the Spirit. He is a worm if he is below the beasts, a slave if he is a normal man, a King if he is a noble man, and God, if he can attain to the divinization of the saints.
Now, there is a continual point to our round in life, a higher purpose, which most of us are dimly aware of at certain special times, which we remember fondly. This purpose could be likened to an aspect of an eternal Spirit which wills to manifest itself (Himself) through us in this particular phase of earthly existence or existence at all. Now, we can achieve this point by an arduous commitment to Truth; yet there is always the possibility that "endgame" can be achieved in any phase of existence, even this one. Rather than the long road, there is a "low road", a sudden illumination, which effectively sets the individual forever within the precincts of God's kingdom. This is what Jesus calls the "second birth". Thus, there is a religion of Christianity that is valid, and there is also a second, faster path or school, which promises greater danger and greater reward - the mystery of the second birth. Christ came to make this second path safe, and to unite it with the "religion" of the first part.
Thus, the individual must become "God's" and also must become God, not by nature, but by participation.