An enemy hath done this - It is the interest of Satan to introduce hypocrites and wicked persons into religious societies, in order to discredit the work of God, and to favor his own designs.

Wilt thou then that we go and gather them up? - A zeal which is rash and precipitate is as much to be feared as the total lack of strict discipline.

Wilt.

Luke 9:49-54 And John answered and said, Master, we saw one casting out devils in your name; and we forbade him, because he follows not with us...

1 Corinthians 5:3-7 For I truly, as absent in body, but present in spirit, have judged already, as though I were present...

2 Corinthians 2:6-11 Sufficient to such a man is this punishment, which was inflicted of many...

1 Thessalonians 5:14 Now we exhort you, brothers, warn them that are unruly, comfort the feebleminded, support the weak, be patient toward all men.

Jude 1:22,23 And of some have compassion, making a difference...

Ears and no Ears
'Who hath ears to hear, let him hear.--MATT. xiii. 8. This saying was frequently on our Lord's lips, and that in very various connections. He sometimes, as in the instance before us, appended it to teaching which, from its parabolic form, required attention to disentangle the spiritual truth implied. He sometimes used it to commend some strange, new revolutionary teaching to men's investigation--as, for instance, after that great declaration of the nullity of ceremonial worship, how that nothing …
Alexander Maclaren—Expositions of Holy Scripture

The Parable of the Tares, by Bishop Latimer, Preached on the 7Th of February, 1553.
MATTHEW XIII.--The kingdom of heaven is likened unto a man which sowed good seed in his field: but while men slept, his enemy came and sowed tares among the wheat, and went his way, &c. This is a parable or similitude wherein our Saviour compared the kingdom of God, that is, the preaching of his word, wherein consisteth the salvation of mankind, unto a husbandman who sowed good seed in his field. But before we come unto the matter, you shall first learn to understand what this word parable, which …
John Knox—The Pulpit Of The Reformation, Nos. 1, 2 and 3.

A Man Reaps More than He Sows.
A MAN REAPS MORE THAN HE SOWS. "But other fell into good ground, and brought forth fruit, some a hundredfold, some sixtyfold, some thirtyfold."--Matt. xiii: 8. If I sow a bushel, I expect to reap ten or twenty bushels. I can sow in one day what will take ten men to reap. The Spaniards have this proverb: "Sow a thought and reap an act. Sow an act, and reap a habit. Sow a habit, and reap a character. Sow a character and reap a destiny." And it takes a longer time to reap than to sow. I have heard …
Dwight L. Moody—Sowing and Reaping