You can become a Christian when you acknowledge that you are a sinner in need of a Savior. Romans 3:23 says “For all have sinned, and come short of the glory of God.” Ask Jesus to forgive you of your sins. Believe in your heart that God raised Jesus from the dead, meaning that Jesus paid the full penalty for your sins. Now confess Jesus as your Lord and Savior, by doing so, would be to surrender control of your life to Jesus and receive Him as your personal Savior forever. Only He can wash you clean from your sins and deliver you from all unrighteousness.
In Romans 10:9 says: That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised Him from the dead, thou shalt be saved. He shall baptize you with the Holy Ghost, and with fire. It is a gift of God, not of you. For you are saved by grace through faith. Now that you are saved, you are a new creature. The old things are passed away, and all things are become new.
Pray to God. Here is a sample prayer. It does not have to be exactly like this one. Father God in heaven, I know that I have sinned against you. I ask you to forgive me of my sins. I thank you for showing your love by dying on the cross just for me. I receive you as Lord of my life and as savior of my soul. Many people who do not believe in Jesus Christ consider themselves Christians simply because they go to church. But going to church, or being a good person does not make you a Christian. Being a member of a church, attending services regularly, and giving to the works of the church does not make you a Christian.
A Christian is someone who has been born again by God. A true Christian is a person who has put faith and trust in Jesus Christ including His death on the cross as He paid the price for our sins and His resurrection on the third day. The mark of a true Christian is love for others and obedience to God’s Word. A true Christian is indeed a child of God, a part of God’s family, and one who has received new life in Jesus Christ.