For Ezra had devoted himself to the study and observance of the Law of the Lord, and to teaching its decrees and laws in Israel.
Ezra devoted himself to three things concerning God's law:
Ezra studied God's law, lived by it and taught it to others. Some people may be called to teach in the same way as Ezra did (a six hour sermon to thousands of people!) but most wont. However, we need to recognise that others are learning from us all the time. Our example, what we say and what we do, in groups or one to one, show both Christians and non-Christians what it mean to follow Jesus. Whether its formal or informal, we are teaching others about God all the time. Ezra was studying, observing and teaching God's law. If we are not studying God, then the "teaching" we are giving to others about what God is like is pointless at best, dangerous at worst. If our lives are not being transformed by God, then people are unlikely to listen to what we are "teaching" them. Let's follow Ezra's example: study God's word, follow it and then tell others about it!