Keep the peace. Thank God for FreeRepublic, where I can shout "I AM PROUD TO BE AN AMERICAN!"
So sorry to hear this horrible news. You are NOT helpless! Maybe this is a really good time to sever those family ties. Sometimes God gives you a strong dose of reality and it really tests you. I think this is that test.
I want to say that this would surely be a mistake. Severing family ties is not the answer. This is the exact type of answer that one would have from Islam, in trying to force someone back into their oppressive and evil religion. And if that doesn't work for them, then killing the individual (in their countries this is definitely done) is the answer. This is not the answer from the true God -- the God of Abraham, Isaac and Jacob.
In fact, He tells us that while we were yet sinners, He loved us enough to die for us, on the cross, thereby providing payment for our sins -- for all who choose Him as their Savior. God did not abandon us -- althought He had every right to do so. It's out of His love for us, that He stays with us, even when we wander away.
In your son's case, with what he has come to believe -- this is very simply deception and evil on the part of the one (i.e., Satan) who seeks to deceive everyone in the world, and destroy their life. This is the fate for all who choose the false god of Allah, while being deceived and following Satan (even unbeknownst to them).
This is not a "battle of religions" -- as if it's a football game. This is -- on the one side -- the God of the Universe (the God of Abraham, Isaac and Jacob), while on the other side is Satan, the liar, the deceiver, the accuser, the murderer, the destroyer.
THEREFORE, your son is deceived and he is deceived by the one who will take his soul. This is the nature of the situation and the gravity of the situation.
And then, you said --
We both realize it's no longer a topic we can discuss.
This is not satisfactory. God would not have it this way. You must persist, although, in a wise way and in a way that will work. That will take some guidance from God on the matter. That will take spiritual discernment and prayerful consideration. But, God will give that guidance -- to those who ask for it. First comes one's personal Salvation, as God's first priority with all is their own personal salvation and not their comfort in society. After that, God's priority extends from you (in your own salvation) to others around you -- in that you can carry the truth of God to them. There must be that kind of priority there -- as that's the way it flows. There are no shortcuts.
Keep the peace. Thank God for FreeRepublic, where I can shout "I AM PROUD TO BE AN AMERICAN!"
If I may speak for all Christians, I can rightfully say that we're all thankful and proud (in Christ) to be Christians. And then we're proud that God has established America to be an "instrument in His hands" -- in this world today and for His chosen nation of Israel (from which nation Christ came and will return again to rule and reign in that land, and over the world).
And so, we're proud that God placed us in America to carry through God's influence in the world. We are proud to be Americans, in that we're proud to be doing God's will in America and throughout the world. To the extent that we can do that, we are proud. God placed us here in this country in order to do His will. That's what we shall do.
In talking to your son, one should be clear about the "founding" and the "basis" for this country -- as it's very evident from many of our founding fathers -- that it was at the hand of God, Himself that this happened. There is no other way or reason that it could have been. If we listen to our founding fathers and many since then -- through even Lincoln during the Civil War, in which he acknowledged the hand of God in our country. This is not the false god of Allah, that deceiver and destroyer. This is the God of Abraham, Isaac and Jacob. This is no "indistinct God" -- but One who identifies Himself, through His word and then finally and fully through His Son, Jesus Christ.
This is the God who founded our country and the One who will preserve and protect it at the present time (even in the midst of, sometimes, much needed chastisement and correction, as a good Father gives his son...) -- to keep it from falling and never getting up. We will be preserved.
This is the God who needs to be brought forward -- to your son -- as a challenge to the false, evil and Satanic god of Allah. In the end, that false god will not stand. Soon we will see the coming of Jesus Christ, our Lord, who will rule over all the nations in the world (including the U.S.) from His throne in Israel. This is soon to come.
You have encountered one of the major "end times" and Satanic religions, which the coming Messiah will destroy as He sets up His Kingdom. This is what you have to be assured of (by what one can know in the Word of God). The time is short, so make good use of it. What we have seen here, on September 11th, is only the opening warning shot of the WAR, which is not only threatening to the U.S. and its way of life -- but will persist until the coming of the Lord and His Kingdom, at which time He will totally and completely destroy it and any followers.
Know this, believe this -- as it comes from the God of Abraham, Isaac and Jacob and is true. He will not disappoint any who call upon His name.