Here’s an encouraging thought:
It is difficult, I admit, not to stumble frequently, and even sometimes to fall, when stumbling-blocks without number lie across our path. But our minds ought to be fortified with confidence; for the Son of God, who commands his followers to walk in the midst of stumbling-blocks, will unquestionably give us strength to overcome them all.
(The history of this parable’s interpretation may be nearly as interesting as the parable itself. What people seem to do is to read “the field is the world” as meaning “the field is the church. Then they read “let both of them grow together” to mean “go ahead and root out the tares immediately.” And I’m not talking about theological lightweights, either. I mean people like Augustine, Calvin, and Wesley.)