Question: "What makes me a believer and Christian?

Answer: An excellent question! To begin with the answer is not "what" but "who." Let me explain. Before I answer, I am making certain assumptions. 

First, my assumption is that a "believer" and "Christian" are the same.

Second, a "believer" or "Christian" is someone who is (1) a redeemed sinner by the redemptive work of Jesus Christ and (2) able to expressly and publicly confess Jesus Christ as his/her Savior and LORD. 

These assumptions do supply some answers to the question already but not all. 

What you do, no matter how much "good" you do or how sincere you are about doing "good," can never make you a believer or Christian. To be a believer or Christian in the sight of God, you must be in a proper God-ordained relationship with Him. Consider Apostle Paul's teaching: 

"And we know that in all things God works for the good of those who love him, who have been called according to his purpose. For those God foreknew he also predestined to be conformed to the image of his Son, that he might be the firstborn among many brothers and sisters. And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified." Romans 8:28-30

So, the question should be rephrased: "Who made me a believer and Christian?" 

When you say that "I am a believer," you are not merely saying that "I am a believer because I have chosen to believe." Biblically speaking, you are a believer or Christian because God has chosen you to be one. 

"For he chose us in Christ before the creation of the world to be holy and blameless in his sight." Ephesians 1:4

"For you created my inmost being; you knit me together in my mother's womb. I praise you because I am fearfully and wonderfully made; your works are wonderful, I know that full well. My frame was not hidden from you when I was made in the secret place, when I was woven together in the depths of the earth. Your eyes saw my unformed body; all the days ordained for me were written in your book before one of them came to be." Psalm 139:13-16

When you say "I believe in God," you are really saying that you understand how God has brought or gifted redemption in you through Jesus Christ and that you trust that it is the case. Your sense or degree of conviction that you are a believer or Christian does not make you one. When God calls you, you come to know and affirm that you are a believer and Christian. While this calling can come or occur in different ways for different people, the end result is the same. You come to acknowledge that your redemption or salvation is from God by His grace received by faith in Jesus Christ.

Thank you for sharing your question and for visiting our website. Hope to see you at our worship some day! Blessings