Jamieson, Fausset and Brown on 1 Kings 18:3

3. Obadiah feared the Lord greatly--Although he did not follow the course taken by the Levites and the majority of pious Israelites at that time of emigration into Judah (2Ch 11:13-16), he was a secret and sincere worshipper. He probably considered the violent character of the government, and his power of doing some good to the persecuted people of God as a sufficient excuse for his not going to worship in Jerusalem.