I don't think anyone needs to practice to sin. Even when we practice not sinning, as Paul said, we fail.
This commentary explains it fairly well.
If we say that we have no sin,.... Notwithstanding
believers are cleansed from their sins by the blood of Christ,
yet they are not without sin; no man is without sin: this is not only true of all men, as they come into the world, being conceived in sin, and shapen in iniquity, and of all that are in a state of unregeneracy, and of God's elect, while in such a state, but even of all regenerated and sanctified persons in this life; as appears by the ingenuous confessions of sin made by the saints in all ages; by their complaints concerning it, and groans under it; by the continual war in them between flesh and spirit; and by their prayers for the discoveries of pardoning grace, and for the fresh application of Christ's blood for cleansing; by their remissness in the discharge of duty, and by their frequent slips and falls, and often backslidings: and though their sins are all pardoned, and they are justified from all things by the righteousness of Christ, yet they are not without sin; though they are freed from the guilt of sin, and are under no obligation to punishment on account of it, yet not from the being of it; their sins were indeed transferred from them to Christ, and he has bore them, and took them and put them away, and they are redeemed from them, and are acquitted, discharged, and pardoned, so that sin is not imputed to them, and God sees no iniquity in them in the article of justification; and also, their iniquities are caused to pass from them, as to the guilt of them, and are taken out of their sight, and they have no more conscience of them, having their hearts sprinkled and purged by the blood of Jesus, and are clear of all condemnation, the curse of the law, the wrath of God, or the second death, by reason of them; yet pardon of sin, and justification from it, though they take away the guilt of sin, and free from obligation to punishment, yet they do not take out the being of sin, or cause it to cease to act, or do not make sins cease to be sins, or change the nature of actions, of sinful ones, to make them harmless, innocent, or indifferent; the sins of believers are equally sins with other persons, are of the same kind and nature, and equally transgressions of the law, and many of them are attended with more aggravating circumstances, and are taken notice of by God, and resented by him, and for which he chastises his people in love: now though a believer may say that he has not this or that particular sin, or is not guilty of this or that sin, for he has the seeds of all sin in him, yet he
cannot say he has no sin; and though he may truly say he
shall have no sin, for in the other state the being and principle of sin will be removed, and the saints will be perfectly holy in themselves, yet he cannot, in this present life, say that he is without it: if any of us who profess to be cleansed from sin by the blood of Christ should affirm this.."
1 John 1 - Gill's Exposition of the Whole Bible - Bible Commentaries - StudyLight.org
So we need to balance how John said no one can say he has no sin, and how he said those that sin are not of god. I find a good balance is to look at the main points of that chapter (1 Jn 3) one of the ways we know people have toe sort of sin he is talking about there is when they are unloving to brothers and sisters. Another major point is that His commandment is to believe. How then do we keep that commandment? Simple, we believe, and then we are not breaking His commandment.
No, they probably, like me, are thinking of something more like 'we do the best we can, and ask for forgiveness as Jesus said (those who never sin would need no forgiving), even many many times as necessary. Being saved is not a license to pretend we never sin and are better than others!