How to determine a genuine call from God?

Imagine one day a person hears voices like God speaking to him (or as how he would describe as God), with bright lights, angels, burning bushes, and all. It would seem so real for him but only he alone heard or experienced it. And the voice would tell him to sacrifice his son/daughter to God. Is it moral for him sacrifice his child because of this experience? it might be a test and if he didn't then he would have failed for doubting God. What would a Christian do?