Sentence:  At one time I became disturbed in the faith in which I had grown up by the apparent inroads being made upon both Old and New Testaments by a `` Higher Criticism '' of the Bible , to refute which I felt the need of a better knowledge of Hebrew and of archaeology , for it seemed to me that to pull out some of the props of our faith was to <WSD>weaken</WSD> the entire structure . 
Meaning of the word marked with <WSD> tags:  lessen the strength of