The deceived are the ones who never read the Word of God. If they know and live His Word and test the spirits, they aren’t deceived.
It is a word of God to you because you choose it to be that. Others choose to believe the Koran, and others yet other writings. You and others have no proof that it is a word of God, except you and they believe it. Keep it that way. I have no quarrel with that, but don't make what you believe a matter-of-fact statement unless you can prove it.