Matthew 10:16

Behold, I send you forth as sheep in the midst of wolves: be ye therefore wise as serpents, and harmless as doves.

The serpent was considered a symbol of wisdom among the ancients, especially the python. The maid at Philippi who followed Paul and Silas was said to have had a "spirit of divination" (Acts 16:16), but the Greek word denotes that she had a PYTHON! Genesis declares that "The serpent was more subtle than any beast of the field" (Genesis 3:1). The dove as a symbol of harmlessness and innocence derived significance from Noah's use of it as a messenger in the ark. See more on the dove under Matthew 3:16.

The brutal and vicious dangers to which the apostles would be exposed were not concealed by the Lord. Their mission was dangerous and fraught with countless perils. The figure "sheep in the midst of wolves" is peculiarly apt and expressive. One wolf in a flock of sheep is a source of incredible slaughter and destruction. Ask any herdsman upon the far slopes of the Rockies how sickening is such a sight! Far worse, even than that, would be a few sheep in the "midst of wolves"!