What would make Judas turn away from the Lord? When one thinks about it, it is incomprehensible, isn't it? It is to me. Yet, this is what he did, so many ask the question: "Why?"
All that can be said with certainty is that which Scripture speaks, but it speaks very little about it. I suppose the "why" is not so important as the action generated by the "why." We always seek to understand the motivation, but while the Lord knows the motivation, He knows very well the actions.
Think about this for a moment. Judas was there when Jesus fed the thousands, not once but twice. Judas was there when Jesus walked on water. Judas was there when the patriotism and nationalism of the religious leaders was so effectively overcome, they went away speechless (only for a short time). Judas was there when Peter was rebuked. Judas was there when Jesus spoke about the one's loyalty and love to Him who is Lord over all.
Was not all this sufficient evidence for one as Judas to stay loyal to the Lord, loving Him by obeying Him? Evidently not.
This brings us to the point of application. When one wants to turn away, there is no amount of information or evidence that will successfully stop one who is determined to leave. All they need is a reason to act; if they can't find one, they make one up.