Before salvation is someone dead in sin?
After salvation can someone still sin?
I recommend you study what Apostle Paul taught about our struggle between our flesh and our spirit per Romans 7. Lord Jesus Christ did not come to save our flesh. He came to save our 'spirit' with 'soul' that is inside our flesh.
Apostle Paul covers this distinction between sin/flesh death and Faith/eternal life of our spirit, per Romans 6. Below is an excerpt of that teaching, which I find many struggle with because they don't really understand what part of our being that God created is saved by Christ.
Rom 6:3-12
3 Know ye not, that so many of us as were baptized into Jesus Christ were baptized into His death?
4 Therefore we are buried with Him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
Our Faith on Jesus' death and resurrection Paul compares to being like a baptism, a spiritual baptism upon our spirit that is inside our flesh. Continuing to read what Paul says here will reveal that "
newness of life" is about our 'spirit' putting on immortality in the world to come.
5 For if we have been planted together in the likeness of His death, we shall be also in the likeness of His resurrection:
That above is a pivot point where many brethren struggle with the idea of our spirit vs. our flesh. At the resurrection, just what did Apostle Paul show in 1 Corinthians 15 that is raised, our old flesh body in ground, or our spirit? Some Churches still preach old Jewish traditions about the resurrection involving a new flesh body, claiming our flesh is raised from the casket when Paul did not teach that. Paul showed in 1 Cor.15 that we shall not all sleep, but that we 'all'... shall be "
changed", meaning changed to the
"spiritual body", which is the type body of the future resurrection per Paul. That must be understood in order to properly understand what Paul covers here next...
6 Knowing this, that our old man is crucified with Him, that the body of sin might be destroyed, that henceforth we should not serve sin.
7 For he that is dead is freed from sin.
The above is where many modern Bible translations insert man-made humanist-humanity doctrines. Apostle Paul is speaking about our flesh body in the above, not some humanity philosophy of man. In Romans 7 Paul covers this point about sin being in our flesh members, so that often when we would do good, we find ourselves doing just the opposite. Paul called it the "law of sin" being in our flesh members, i.e., our flesh body. Once our flesh dies, we are freed... from that state of sin that our flesh causes us.
8 Now if we be dead with Christ, we believe that we shall also live with Him:
9 Knowing that Christ being raised from the dead dieth no more; death hath no more dominion over Him.
10 For in that He died, He died unto sin once: but in that He liveth, He liveth unto God.
How does Lord Jesus
"liveth unto God" after His resurrection? Apostle Paul in 1 Corinthians 15:50 said that flesh and blood cannot inherit the Kingdom of God. And Peter in 1 Peter 3 showed that Christ's body was 'quickened' by The Spirit. Afterall, Christ had no flesh body before He was born as Jesus in Mary's womb, yet He always existed. It's because like Apostle John said in John 4:24,
"God is a Spirit".
11 Likewise reckon ye also yourselves to be dead indeed unto sin, but alive unto God through Jesus Christ our Lord.
12 Let not sin therefore reign in your mortal body, that ye should obey it in the lusts thereof.
KJV
Likewise, those of Faith are to reckon (suppose, assume), to already be dead though we are yet alive in our flesh, like having already put off our flesh body, which is the
"body of sin", and having already been resurrected with Lord Jesus Christ. That is how our behavior in Christ is supposed to be, according to Paul in the above Romans 6 chapter.
What then does this point to about our life today while still alive in the flesh on earth? It points to sin in our fleshy members, because most of our sins are caused by fleshy lusts and desires, and walking by our flesh instead of walking by The Spirit in Christ Jesus (Galatians 5). As long as we are still in the flesh, we will have this struggle between our spirit and our flesh, for they are two separate orders of operation.
Like Jesus said:
John 3:6
6 That which is born of the flesh is flesh; and that which is born of the Spirit is spirit.
KJV