Unbelief is the root of all sin in Christians. What kept the children of Israel from entering into the promised land? Unbelief. They sent spies, for they thought their testimony would corroborate God's word to them. It is true the spies brought back a bunch of grapes so big that it took two of them to carry it; but, when a heart sends spies to corroborate' God's word, a bunch of grapes is not enough to make a soul that is not true go into the land.