<my question is then why do we still sin? it seems to me that the holy
spirit would be in us, and we would be under our king Jesus reign, and
not want to sin,>
Good question. Wish I had all the answers to tell you, however, I don't think anyone has them all...I will tell you my understanding from what I've studied in the Bible. As a disciple of Christ, the Holy Spirit should indeed indwell us...His fruit abounding in our life. He is truly our Helper, comforter, and intercessor. And truly we should be under the Reign of Christ as our King. Yet we have one problem....we live in the flesh...we are weak by the flesh, we are not God we are not deity we are simply created as fleshly beings with a priceless soul. For God's purposes He has decided that we should live in these earthly vessels in the physical world for a period of 75 to 100 years generally these days. God knows that this life is incredibly difficult for man and gives His children His Spirit to help them. The apostle Paul sheds light on the topic and even he says:
Rom 7:18-25
18 I know that nothing good lives in me, that is, in my sinful nature. For I have the desire to do what is good, but I cannot carry it out.
19 For what I do is not the good I want to do; no, the evil I do not want to do-- this I keep on doing.
20 Now if I do what I do not want to do, it is no longer I who do it, but it is sin living in me that does it.
21 So I find this law at work: When I want to do good, evil is right there with me.
22 For in my inner being I delight in God's law;
23 but I see another law at work in the members of my body, waging war against the law of my mind and making me a prisoner of the law of sin at work within my members.
24 What a wretched man I am! Who will rescue me from this body of death?
25 Thanks be to God-- through Jesus Christ our Lord! So then, I myself in my mind am a slave to God's law, but in the sinful nature a slave to the law of sin.
(NIV)
Paul says that it is because we are in the flesh that the evil one is able to trip us up. He was a man who no one can doubt was filled with all the power of the Holy Spirit and yet he says these things about himself. All of Christ's disciples will stumble in their walk and sin. It is the Holy Spirit who gives us strength through the down times to nudge us back to the Way. We can choose to refuse the help and if that happens we shipwreck our faith. We should not think we will be sinless as Christians.
I Jn 1:8-9
8 If we say that we have no sin, we deceive ourselves, and the truth is not in us.
9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
(NKJ)
Thank you Jesus for your Grace and forgiveness :)
hope this helps in some small way.