You most certainly don't have to sin! Christ most certainly did condemn sin in the flesh and we are dead to the Law we can't keep.
Sin most certainly will not have dominion over you if you walk in the Spirit surrendering yourself to the will of the Holy Spirit.
But here is the fact of fallen man: The Spirit is willing but the flesh is weak.
We can't measure up to the position God has placed us in, that's why it's called Grace!
By our faith in Christ, God has promised to bring us to that level at the resurrection.