The Bible says that the thing that separates the true Christian from the one who merely professes to be one is their fruit. There is another distinction that separates the two as well. It is their attitude toward the Word of God.
Those who are true Christians eat the Word, take joy in the Word, rejoice over the Word and love the Word. They pattern their lives after the principles found in the Word. They let it direct their lives. They follow its instructions. They allow the Word to conform their way of thinking, their responses, their attitudes and their conduct. They try to live their lives in such a way where it lines up with the Word of God. They are living by the Word. They are doers of it and not just hearers only. They are not living their lives contrary to its teachings. They are not rebellious against what it says. They are allowing it to transform their lives.
Those who have a mere profession of Christianity take the Word for granted. They follow their own course in life. They do their own "thing". They make their own decisions and guide their own lives. The Word doesn't have importance to them. They may read it and hear sermons on it, but when it comes to applying it to their lives or living by it, they choose to live by their own rules and desires.
You may be calling yourself a Christian, but if you don't have a love for the Word of God and are allowing it to be the standard by which you live, you are fooling yourself. The verse above says that those who love the Word are called Christians.
Have a great day. True Christians love the Word of God and live their lives by it.