You said a Christian is one who “obeys God”.
Disobedience is sin.
A Christian is a son or daughter of God, they are no longer a slave to sin.
John 8:34-36
34 Jesus answered them, “Most assuredly, I say to you, whoever commits
sin is a slave of sin. 35 And
a slave does not abide in the house forever, but a son abides forever. 36 Therefore if the Son makes you free, you shall be free indeed.
1 John 3:21-23
21 Beloved, if our heart does not condemn us, we have confidence toward God. 22 And whatever we ask we receive from Him, because
we keep His commandments and do those things that are pleasing in His sight. 23 And this is His commandment: that we should
believe on the name of His Son Jesus Christ and love one another, as He gave us commandment.
1 John 3:4-6
4 Whoever commits sin also commits lawlessness, and sin is lawlessness. 5
And you know that He was manifested to take away our sins, and in Him there is no sin. 6 Whoever abides in Him does not sin. Whoever sins has neither seen Him nor known Him.
So...what did you do to become a “Christian”?
Repent, not just from the sins you've been committing, but from your whole sin nature. Believe that only Jesus can save you from your sin nature. It is more than just knowing facts about Jesus, even the demons know that. You must be born again of the Spirit. In other words receive a new spirit and a new nature - the divine nature.
Acts 2:38
38 Then Peter said to them, “Repent, and let every one of you be baptized in the name of Jesus Christ for the remission of sins; and you shall receive the gift of the Holy Spirit.
Romans 8:1-9
8
There is therefore now no condemnation to those who are in Christ Jesus,
who do not walk according to the flesh, but according to the Spirit.
2 For the law of the Spirit of life in Christ Jesus has made me free from the law of sin and death. 3 For what the law could not do in that it was weak through the flesh, God did by sending His own Son in the likeness of sinful flesh, on account of sin: He condemned sin in the flesh, 4 that the righteous requirement of the law might be fulfilled in us who do not walk according to the flesh but according to the Spirit. 5 For those who live according to the flesh set their minds on the things of the flesh, but those
who live according to the Spirit, the things of the Spirit. 6 For to be carnally minded
is death, but to be spiritually minded
is life and peace. 7 Because the carnal mind
is enmity against God; for it is not subject to the law of God, nor indeed can be. 8 So then, those who are in the flesh cannot please God.
9 But you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. Now if anyone does not have the Spirit of Christ, he is not His.