Jas 5:19 Brethren, if any of you do err from the truth, and one convert him;
Jas 5:20 Let him know, that he which converteth the sinner from the error of his way shall save a soul from death, and shall hide a multitude of sins.
A Spirit led life will abstain from sin,because the person does not want to sin,but that does not mean we will not sin,for we can sin if we desire to sin,but as long as we do not want to sin we cannot abstain from sin by the Spirit.
It is obvious that a person that has been saved can hold unto a sin,for it is not talking of someone that sins,but gets rid of it right away,but a person that holds unto sin,and when in that condition they have erred from the truth,and have to be converted again,like the world that holds unto sin,until they confess Christ,not wanting sin,and if we sin willfully,hold unto sin,there is no more sacrifice for that sin,for Jesus' blood cannot wash away a sin that someone holds unto.
So a person can be saved,and go back to holding unto sin like the world without the truth,and if they stop holding unto it,and get concerted back to the position of not wanting sin,it will hide a multitude of sins,for when someone holds unto a sin they will do it quite frequently,and the more sins they hold unto the more sins they commit.
I do not believe a lot of people that confessed Christ actually started off wanting no sin in their life,because of a lot of preachers that say they cannot beat sin,so they repent of their sins,are sorry for what they done wrong,but do not give up the sins,which is true repentance.
As in the case that they have a form of godliness,but they deny the power thereof,ever learning and never able to come to the truth,and the people that said Lord,why can't we dwell with you,He will say you were workers of iniquity,and I never knew you.
So some people that claim Jesus as Lord,and confess Him,did not properly repent of their sins,and receive the Spirit,and that is due to preachers that preach they cannot abstain from sin,but God said,if you do not want sin,and mean it,by the Spirit you can abstain from sin.
A lot of people got the wrong start from the get go,and that preaching that sin does not affect their relationship with Christ,but God said,if they hold unto sin,they need to get rid of it,and it will hide a multitude of sins.