Christ's mandate to us that we become "wise as serpents and harmless as doves" implies that we must develop discernment, the ability to detect motivation and the spirits that motivate. The gift of discerning the spirits will become increasingly important as we approach the end of this age because deception will be the hallmark of these extremely dangerous times.
In the Olivet Prophecy, the disciples ask Jesus to reveal the sign of His return. Jesus does not give one sign but several. At the top of the list, he warns the disciples of deception, and follows it up with warnings of false prophets, false miracles, and the warning not to be deceived (see Matthew 24:4-5, 11, 23-26).
We deduce from this last warning that false "Christian" ministers and ministries will have the capability of performing convincing lying wonders and signs. These false ministers will demonstrate power—occult power—for the specific purpose of leading all people astray, including the most sincere believer.
We have a clear warning from the apostle Paul that the battles we face on a daily basis cannot be won by conventional weapons that we can attain from the world. The weapons we must seek should be spiritual, having the power to destroy arguments and every false claim that sets itself up against the knowledge of God and God's Word (II Corinthians 10:3-5).