There are other “spiritual voices,” too. It is in contrast with the kind of voice I have just described [God’s voice] that the voice of our adversary, Satan, is made known to us, for he too will speak in our heart once he sees he no longer holds us in his hand. Only if we learn to recognize his voice as well can we avoid many silly attributions of events to Satan (“The devil made me do it!”). And only so can we correctly identify and firmly resist him and make him flee from us (1 Pet 5:9; Eph 6:11).
Satan will not come to us in the form of an oversized bat with bony wings, hissing like a snake. Very seldom will he assume any external manifestation at all. Instead he will usually, like God, come to us through our thoughts and our perceptions. We must be alert to any voice that is in contrast with the weight, spirit and content of God’s voice, for that may signify that we are under subtle attack.
The temptations of Jesus in Matthew 4 illustrate this well. It does not take much imagination to realize that if some bat-like creature suggested to Jesus that he turn the stones into bread, this would certainly have tended to curb his appetite. How then did the tempter come to him (v. 3)? Actually the Gospel passages give no indication as to how he came.
Perhaps—and this is just a suggestion—as Jesus suffered extreme hunger, the stones about him reminded him of—perhaps began to look like—the loaves from his mother’s oven. Perhaps he began to smell them and then to think how easily he could turn those stones into such loaves—with butter. But then he also realized the conflict between this vision and the great truth that the word of God is a substance, a meat (Jn 4:32). He refused to allow himself to be turned away from learning that God’s word is sufficient for his every need. Human beings live by every word that issues from God’s mouth (Deut 8:3). The voice of temptation was clearly opposed in spirit and content to God’s word, and Jesus recognized Satan and successfully resisted him in this and in the other temptations which followed.
Likewise, followers of Christ must be encouraged to believe that they can come to understand and distinguish the voice of God. They need only to look within their thoughts and perceptions for the same kinds of distinctions as they would find in spoken or written communications received from other human beings: a distinctive quality, spirit and content.
All of the words that we are going to receive from God, no matter what may accompany them externally or internally, will ultimately pass through the form of our own thoughts and perceptions. We must learn to find in them the voice of the God in whom we live and move and have our being.
Dallas Willard, Hearing God: Developing a Conversational Relationship with God, 181, 182.