My sheep hear my voice, and I know them, and they follow me…A stranger they will not follow, but they will flee from him, for they do not know the voice of strangers.” –John 10:27,5
A serpent doesn’t sound like a lamb, and a serpent doesn’t sound like a lion either!
There’s a characteristic difference in the voice of God.
The reason we’re deceived at times is because we’re listening to the words only and not the characteristic sound of The Voice.
If you go back and think of the times that God spoke to you, that you know it was Him, you’ll be able to identify a characteristic voice.
If you think of the times the enemy has spoken to you, you will also be able to identify a characteristic voice in that.
So the key to discernment goes beyond just the words that are spoken, because Satan uses scripture as well. You must listen to the characteristic sound of the voice to identify who it is that’s speaking.