You are correct. You either are a Christian or you are not.
My friend, I am a man who likes evidence. I would absolutely love for there to be aliens, but I do not believe in them because there is no credible evidence that they exist. When evidence is presented, I will examine it for credibility. Likewise, I do not believe in ghosts. I have never seen one nor seen credible evidence of one. I am like that with everything in my life. Show me the evidence.
I am a committed Christian, and live by Faith in God and our Lord Jesus Christ. Why? Because of incontrovertible evidence. But it is not evidence that I can take out and show anyone. It is evidence in my heart, and in my life, and in the lives of people I know and love.
Most people will not believe it, and will not see it, nor will they understand it. Including some on this post. That saddens me, but there is nothing I can do, except let Jesus light shine through me as best I can, and pray for them. But we are not bound by their choices or their beliefs or approvals. We will spend eternity with God who loves us. I look forward to meeting you there.

Let me address this again, a little more directly.
EVERYONE is directed to follow God's 'rules'. Those who accept Jesus as their Lord and Savior do their best to follow God's commandments, and to live their lives in such a way that He will be glorified. We all fall short, but do our best each day. These people are Christians. All non-Christians are still children of God, and He loves them and craves that they will someday accept Him as well.
The idea that "I am not bound by the rules of God because I'm not a Christian" is logical nonsense, just as saying "I am not bound by speed limits because I'm not a licensed driver". Both will get you in very serious trouble. The former will cost you an eternity separated from God.