wouldn't a jw say that the father only welcomed him back because he no longer was 'sinning'?
Yes, thats why he accepted him. The key is, that was all that was necesary. Dubs want you to stop sinning, come to the meeting for 6 months, sitting in your shame at the back of the hall, than write a letter saying how sorry you are and that you will like them to consider re-instating you. That is some Bull-CaCa. The father immediately welcomed his son back into his life.
By placing extra measures and requirements on penitence, the dubs have eliminated Christ vision and supplanted it with their own. The only requirment that Jesus laid out to be forgiven of your sins, was to stop doing them. The way of true christainity, at its base level, is very pure and Idealic. Over the course of centuries and a millenia, religions have added on there own rules. When you burn away these added rules and regulations, what you are left with is the pure and simply version that christ left for us.
I believe that it is human nature to take a belief and rationalize and make it your own. In and of itself there is nothing wrong with this. But, when you try to force your incorporated beliefs on others thats where it begans to be watered down and erodes the real meaning of christ teachings.