There is a great truth going on here (when is there not). You can treat everyone through the rules and that’s what Simon did to the woman who anointed Jesus’ feet with her tears and wiped them with her feet. Or you can treat everyone through forgiveness and that’s how Jesus treated the woman.
The problem with treating everyone by the rules is that usually it comes back on you because you probably haven’t quite played by the rules also, lets be honest! That’s Simon’s problem, he hasn’t treated Jesus properly by washing this feet but the woman did by anointing his feet and treated him well after the journey there.
The parable Jesus uses to quieten Simon’s protestations confirms the truth that if you treat people through forgiveness then no one has power over the other, not just in terms of authority or position, but you also release folk from your grudges and bitterness towards them, that holds not just them but you. It’s amazing. Imagine that. Rules rely on taking out trust and compassion from our relationship, telling people to live towards each other in a particular way. Forgiveness is all about genuine relationship based on trust and compassion.
It’s a choice about how we wish to live in community, and it has to be a choice. You can’t turn forgiveness into a rule in itself, that defeats the purpose of forgiveness. It’s always a choice. That’s why it works.