Someone asked me how loving others could lead to theosis.  Here is my response:
To answer your basic question: yes, focusing on loving others (i.e. the virtues) leads to unceasing prayer precisely because we continually fail.  Failure teaches us (not in theory but by the intimate knowledge of experience) that we are utterly dependent on God’s Grace at every moment.  Consequently, one who strives to love comes to pray unceasingly in her heart because she is always painfully aware of her tendency toward selfishness and her bad habit of not attending to the suffering and needs of others.  Not wanting to be a cause of suffering or scandal or trial to others, she prays in her heart, with pain in her heart, for Grace and mercy and help.  She continually appeals to the Saints and the Mother of God for guidance and intercession.  
The fruit of this is not that she becomes aware of her closeness to God.  No, the opposite is true.  She becomes more aware of her weakness and dependence on God for help.  This, however, is exactly what the Saints experienced: “When I am weak, then I am strong.”  The more dependent you are on God’s help, the more God can work through you—but you won’t particularly notice it; or rather, it will seem as though God is being ridiculously good, so much more than you deserve (for you will only see your weakness).
So much of our Christian growth is accomplished in “the patient continuance in doing good.”  But we cannot patiently continue to do good in our own strength.  We fail continually; but through the pain of not being able to love God and neighbour as we want to love them, we are driven to ceaseless prayer.  And in ceaseless prayer, we come to know God’s strength and our weakness.  This is what the beginning of theosis looks like.