When a person has overcome one temptation and his faith has been tried in it, there upon he comes to another, and he passes as it were from one stage to the next; and when he has mastered whatever may befall him and faithfully endured it, he goes onto another. And thus he is said to have proceeded by stages as he submits to each of the trials of life and the tests of faith, and in them the virtues are acquired one by one. Likewise in them there is fulfilled what has been written, "They shall go from strength to strength” [Psalm 84:7], until the final stage is attained, which is the summit of the virtues, and the river of God is crossed and the promised inheritance is received.
ORIGEN Homilies on Numbers