Much truth here:
Satan loves to trip us over little things. The reason for this is that it is generally a greater victory for him and shows that he can upset us by a shaving and knock us down with a straw. It is the old boast of the Jebusites, when they told David they could defend Jerusalem by a garrison of the blind and lame.
The little foxes spoil the vineyard. The minor irritations of life often sour our attitudes. The evil one will pull us down at once or by degrees, however he can.