The Bible says that those that name the name of Christ has to depart from iniquity,which if a person hates sin,and does not want sin,by the Spirit they can abstain from sin.
If we sin it can be forgiven,and if we hold unto sin for a year it can be forgiven.Sin can be forgiven at all times.
If we sin wilfully there is no more sacrifice for sins,which means if we hold unto sin the blood of Jesus cannot take it away,for we will not let it go,but if we let it go,and do not want it,and mean it,the blood of Jesus will take it away.
We can be forgiven of sin,and even if we hold unto sin,and let it go,it can be forgiven,but holding unto sin is a risk factor,for we might get caught up in the flesh,and not overcome,and perish from off this earth with that sin.
God knows the heart,and whether a person gives up sin,or not,and Jesus preached repent,and that repent is from them on,that we turn away from sin,so holding unto sin,and not giving it up,the blood of Christ cannot wash it away,and it is on their record.