<p>17:19&nbsp;<em>Then came the disciples to Jesus privately, and said</em>- In a house (Mk.).&nbsp;</p>
<p><em>Why could we not cast it out?</em>- They were surprised at their inability, which suggests they had performed such cures before and had faith that they could do miracles. The Lord's explanation in the next verse that they had no faith (&quot;unbelief&quot;,&nbsp;<em>a-pisteo</em>, no faith) would therefore have been hard for them to initially accept. His idea was that we either believe or do not believe, and often what seems to us as faith, even if it is admittedly small faith, is ultimately not faith. John's Gospel even more clearly presents faith as something one either has or doesn't have. And yet in reality there are gradations of faith, and the Bible recognizes this. The Lord's next comment that &quot;<em>If&nbsp;</em>you [really, as you think] have faith as a grain of mustard seed...&quot; was therefore speaking to their assumption that although their faith was small, they did actually believe. Again we see how the Lord sees to the inner, unexpressed thoughts and positions of His audiences, and addresses them. This presentation of faith as an absolute, a black or white position (and John's Gospel stresses this even more), is a huge challenge to examine our faith.</p>