Doves And Serpents

Estote ergo prudentes sicut serpentes, ad intelligandas fraudes. Estote simplices sicut columbae, ad ignoscendas injurias. Nolo vos esse semper quasi columbas, ne propter simplicitatem nimiam per seductionem laqueum incurratis. Nolo vos esse semper sicut serpentes, ne ex corde contra aliquem venena fundatis, sed secundum tempus et personas mutetis et mores. Estote serpentes, ne comprehendamini. Si enim comprehensi fueritis, estote columbae, ut ne mordeatis. Quamdiu enim homo gentilis est, serpens in illo est: quoniam indignatio illius secundum similitudinem est illius serpentis, qui in paradiso hominem a Deo separavit: cum vero converitur ad fidem, recedente serpente, ingreditur in illum Spiritus, qui in specie columbae descendit de caleo et fit columba. Ergo contra infideles estote serpentes, quia serpens serpenti non nocet: cum fidelibus autem estote columbae, ut quasi columbae columbis caritatis oscula porrigatis. Et ut breviter dicam, estote prudentes sicut serpentes, ut malum intelligatis et caveatis. Et estote simplices sicut columbae, ut non faciatis ullum malum. Quia intelligere malum, laudabile est: facere autem vituperabile. Nec qui intelligit malum, ipse facit malum, sed qui facit malum. Opus Imperfectum in Matthaeum, Homilia XXIV Source: Migne PG 56.758

Be, therefore, as wise as serpents, for the understanding of deceit. Be as simple as doves, for the forgiveness of injuries. 1 I do not want you to be always like doves, lest because of your utter simplicty you fall into snares by seduction. I do not want to be always like serpents, lest you pour out on someone venom from your heart. According  to times and persons adapt your behaviour. While a man is faithless the serpent is in him, and his hostility is like that of the serpent who in paradise separated man from God; when, however, he turns to the faith, the serpent withdraws and the Spirit enters into him, He who in the form of a dove comes down from heaven, and He makes a dove. Therefore, against the faithless be serpents, because a serpent does not harm a serpent. With  the faithful, however, be doves, that as a dove to a dove you offer the kisses of charity. And if I may speak briefly, be as wise as serpents, so that you have understanding of evil and are wary of it. And be simple as doves, so that you do no evil. Because to understand evil is praiseworthy, to do it worthy of reproof. It is not he who understands evil who is the evildoer, but he who does it. Opus Imperfectum on Matthew, from Homily 24 1 Mt 10.16