God raised Cyrus up to do His bidding to prove to him and all the world who is the true God! God went before Cyrus (verse 2), paving the way for his victories and policies so that His will and His plan would move forward. We should be able to look back at history and see how God worked to bring all the necessary elements into place for His purpose to be fulfilled.
After God used Nebuchadnezzar to punish His people, He raised Cyrus to deliver them from their captivity in Babylon and return them to their land. For the real Christ to be born in Bethlehem as the prophecy states, Jews had to be living in Judea. He also inspired Cyrus to institute his conciliatory policy toward foreign religions so that a Temple could be built to which His Son could come. And among other points, Jerusalem had to be rebuilt so Jesus could die outside the city for our sins.
No other "god" can do these things! Only the Most High God, the Almighty Sovereign of the universe can work out events over such long periods of time. He can take sinful men who have never even desired a relationship with Him and cause them to do His will and bring about His purpose.
God is in control. Light, darkness, peace, or calamity—none of these things happen without His permission. "I, the LORD, do all these things," He says.
Richard T. Ritenbaugh
Cyrus: God's Anointed
Ezra 1:1-2 states that Cyrus issued a decree to free the Jews in the first year of his reign over Babylon. Since Cyrus conquered Babylon on October 12, 539 BC, the first year of this reign was 539-538 BC. God through Isaiah, then, named him at least 143 years earlier. What God did through Cyrus also fulfills a prophecy made through Jeremiah (Jeremiah 25:11-14) sometime during the century following Isaiah's death. Ezra distinctly says that God stirred up the spirit of Cyrus to perform this and that Cyrus claimed that God commanded him. Ezra 1:5 states that God also stirred the spirit of the Jews, Levites, and Benjamites to return to Jerusalem to build the Temple, confirming His sovereignty over the whole affair.
John W. Ritenbaugh
The Sovereignty of God: Part Five