Altar restored, October 538 B.C.

When the exiles returned from Babylon "the altar was dedicated in October of the memorable year, 538 B.C. " (Keyes, 1962).

Ezra 3:2-3 "Then stood up Jeshua the son of Jozadak, and his brethren the priests, and Zerubbabel the son of Shealtiel, and his brethren, and builded the altar of the God of Israel, to offer burnt offerings thereon, as it is written in the law of Moses the man of God. And they set the altar upon his bases; for fear was upon them because of the people of those countries: and they offered burnt offerings thereon unto the LORD, even burnt offerings
morning and evening."

The Israelites were worried about the people around them. But that worry did not stop them from building God's altar and worshiping there. The altar was built on Mt. Moriah where Solomon's Temple had been. What bravery! These people had to build and worship at the top of a hill while there were threats around them. We Christians have that same strength available to hold onto God's narrow way.

Reference:
Nelson B. Keyes. (1962). Reader’s Digest Story of the Bible World.
Pleasantville, New York: The Reader’s Digest Association.