But the Kinders, like the rest of us humans, have a hard time obeying. It's not that we are ignorant, or even openly defiant, yet we struggle so deeply with obeying to the fullest extent, obeying from the heart. Even Paul, God's chosen apostle to us Gentiles, admits this about himself. It is a fault as rampant and widespread as humanity itself. We are incapable of keeping covenant.
So, God created a new covenant.
First, He came as Jesus to fulfill the old covenant and make a way for the new. This, as always, required blood-- which Jesus willingly gave. This allows God to forgive us.
Then, He came as the Holy Spirit, to dwell with any human who would have Him, thus empowering us to be attentive to Him and His laws, and, being a new creation, live by the Holy Spirit's power, and, gradually be transformed into the likeness of Christ.
Trying to keep the law, and then making sacrifices when it isn't kept, didn't train the Israelites to have heart obedience, so why do we think a behavior chart will work with kids? If indeed it was successful in training them to obey the idea behind the rule, we wouldn't need it at the end of the school year, much less every recurring year. Instead, Kinders are still losing 'smilies', and Christians are still falling short of God's standards. In both cases, we need God living in us, and our own attentiveness and obedience to Him, for there to be any true heart change and victory in living.