"weakness" is a symbol of spiritual weakness, lack of human ability to correctly understand the figurative sayings of the Prophets, Christ and the Apostles and to constantly implement God's Commandments, to live according to the Teachings of Jesus Christ.  

"weakness" is a figurative characteristic of man's tendency to please the sinful demands of the flesh, to justify his sinful deeds, the inability to overcome his sinful desires, the manifestation of powerlessness in the face of various temptations to violate God's Commandments.