Does legalism only mean temple worship and Judaism?
No. Legalism is not limited to temple worship and Judaism. It appears in many shapes and forms, always subtly, because it appeals to the human concept of having to do something. In contrast, Paul's doctrine teaches believers do nothing but rest on and believe what God has finished on their behalf through Christ's death, burial, and resurrection.
Les explains that people normally think of legalism as just temple worship and Judaism, but that is too narrow. Legalism comes in all kinds of shapes and forms and is always subtle. It appeals to the human concept of 'I have to do something.' Paul's doctrine, by contrast, says we do nothing but rest on and believe what God says He has finished on our behalf. That is the Gospel—the death, burial, and resurrection of Christ. This false teaching of legalism plagued the Galatian churches and has continued through the centuries, remaining just as relevant today.