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
The Bible declares quite clearly that God is not only well aware of what is taking place, but He also has the power, wisdom, and love to either stop it at any time or let it run its course. In fact, Scripture plainly shows God actively—indeed proactively, not merely permissively—involved in earthly matters. God has not gone "way off somewhere," letting things simply proceed naturally.
John W. Ritenbaugh
Is God to Blame?
Until this point, the prophecy foretells a wonderful event, but verse 7 introduces a sobering side of God's work: He creates calamity! He links two contrasting sets of events: light and peace—representing constructive, hopeful, encouraging events—against darkness and calamity—representing destructive, fearful, discouraging circumstances. God creates both "good" and "bad" circumstances for His people and purpose.
John W. Ritenbaugh
God's Sovereignty and the Church's Condition (Part One)
Other Forerunner Commentary entries containing Isaiah 45:7: