Every Christian CAN know the voice of God but very few Christians can honestly say that they hear the Holy Spirit clearly and commune with Him regularly.
In John 10:3-4 Jesus calls His followers sheep and tells us that His sheep will know His voice and will follow Him.
“3 To him the porter openeth; and the sheep hear his voice: and he calleth his own sheep by name, and leadeth them out. 4 And when he putteth forth his own sheep, he goeth before them, and the sheep follow him: for they know his voice.”John 10:3-4
The enemy will use all sorts of things to try and convince you otherwise, but you CAN hear the voice of your heavenly Father. The voice of the Father, and the voice of Jesus come to us through one source. All of the Godhead speaks to us in the earth through the Holy Ghost. When one speaks, they all speak, and they never contradict each other.
In John 8:47 Jesus put it another way. He says, “He that is of God heareth God’s words:”
If you are of God, you can hear Him speak to you. Learning to hear God talk to you begins with believing that you can hear God, and then using your faith, listen.