Regarding the command "sin no more" this happens twice in John and is specific to the two people Jesus was interacting with. In both cases, Jesus knew something of their particular circumstances where some manner of habitual behavior or living had resulted in their extremely dire situation at the time he healed or forgave them. So it is not a universal template on how anyone comes to faith in Christ and repents. The rest of the New Testament is consistent that the life of the believer involves a process of struggling with sin. Paul for instance never tells the churches he writes to for everyone to simply "sin no more". He says now that they have died to sin and been made alive with Christ, they must persevere in the process of putting to death the sinful deeds of the flesh, for this is consistent evidence of our new identity in Christ as a new creation, though we still inhabit corrupted bodies in a corrupted world. But for particular sins that are tearing apart the Church, or scandalizing the Gospel message, Paul gives the pastoral command to deal with it decisively (1 Corinthians examples: the petty divisions, the incestuous relationship a man had with his stepmother, etc. Galatians example: the false teaching to require circumcision and law keeping to be saved. Hebrews example: the temptation to return to Judaism for assurance of salvation, etc)

Of course making an unforced decision is involved in coming to faith in Christ. But unfortunately American evangelicalism has in some ways made mankind's natural ability to "choose" into a work an in some cases even an idol. I used to be in that world. It's a democratic libertarian distortion of Christianity. The NT teaches we in our natural state don't even have the ability to choose correctly without the regenerative and sovereign work of the Spirit upon the heart. Remember in John Jesus also told his disciples, "You did not choose me, but I chose you". Wait, what? They chose to follow him didn't they? Yes, because once they are no longer dead in sin and darkness but are His sheep (sovereign work of the Spirit), they hear His voice and follow.

Of course making an unforced decision is involved in coming to faith in Christ. But unfortunately American evangelicalism has in some ways made mankind's natural ability to "choose" into a work an in some cases even an idol. I used to be in that world. It's a democratic libertarian distortion of Christianity. The NT teaches we in our natural state don't even have the ability to choose correctly without the regenerative and sovereign work of the Spirit upon the heart. Remember in John Jesus also told his disciples, "You did not choose me, but I chose you". Wait, what? They chose to follow him didn't they? Yes, because once they are no longer dead in sin and darkness but are His sheep (sovereign work of the Spirit), they hear His voice and follow.