Isaiah 45:5

I am the LORD, and there is none else, there is no God beside me: I girded thee, though thou hast not known me:

The Lord alone is God, and there is no other God beside Him. This was His own message to Cyrus the Great, spoken more than a hundred years before his birth, by which He girded, strengthened, equipped and directed Cyrus to subdue nations even though Cyrus did not know Him. He did this so that people from east to west would learn His sole sovereignty, and Cyrus, recognizing the prophecy concerning himself, was moved to fulfill his appointed mission to set the Jewish captives free and help restore the temple at Jerusalem. As He girded Cyrus, He still imparts power to every earthly ruler and directs rulers, nations and the affairs of His church through agents who may not know Him. Therefore His people are to seek wisdom from Him and trust Him alone rather than looking to finite man or other powers, going forward as instruments in His hands and giving Him the glory for the ability and success He bestows.

Cyrus and Sole Sovereignty

The Lord alone is God, and there is no God beside Him, no other beside Him and no other source of divine help.
The declaration is God's own message to Cyrus the Great, written more than a hundred years before his birth, in which the Ruler of the universe girded, strengthened, equipped and directed Cyrus for his work of subduing nations even though Cyrus did not know Him.
He so girded and empowered one who did not know Him in order that people from the east to the west, people everywhere, would learn that there is no God beside the Lord and His sole sovereignty would be made known.

Cyrus was moved as God's agent to carry out His purpose for Israel when he recognized this prophecy concerning himself, which Daniel already knew, and seeing it moved his heart to fulfill his divinely appointed mission to set the Jewish captives free and help them restore the temple of Jehovah at Jerusalem.
The verse belongs to a passage that very fully reveals God's purpose for His people and is to be prayerfully studied, directing them to seek wisdom from Him and not from finite human beings.

The surrounding passage connects the Lord's rule with salvation to all the ends of the earth for those who look unto Him alone.
That looking brings blotting out of transgressions as a thick cloud, return and redemption of Jacob, and righteousness and strength in the Lord.
It brings justification and glory for all the seed of Israel, with every knee bowing to Him and every tongue swearing, all who were incensed against Him ashamed, and heavens, earth, mountains and trees breaking into singing because the Lord has glorified Himself in Israel and His glory, righteousness and salvation spread through the progress of His kingdom.

God's Rule Over Rulers

The power exercised by every ruler on earth is imparted by Heaven, for the Lord girds and strengthens each ruler though he has not known Him. Each ruler's success depends on how he uses the power thus bestowed.

As He girded Cyrus for His purposes, God directs the work of rulers and other agents who may not know Him. He guides the destiny of nations and the affairs of His church, even through coming crises. Workers are instruments in His hands, while His guidance and the ministry of heavenly beings direct the work.

His greatness and majesty are displayed in grand scenes of nature. Seeing His marvelous works humbles human self-estimate and fills the heart with serious and solemn thoughts of God that move to praise and worship. The same girding though not truly known applies to many who claim to know God while holding false, dishonoring ideas of Him. Their lack of true knowledge is the result of Satan's work to misrepresent the Father and the Son. God will give light and knowledge of spiritual things to those willing to discern them, and this knowledge they are to give to others.

God will show before a world transgressing His holy law that He alone is God with no other beside Him. His terrible denunciations of sinful practices are made more awful because He has placed restraint upon His own prerogatives and power. He has borne long with the deceptions of men claiming piety, and while provoked by their impieties has inflicted less punishment than they deserved. His supreme authority as the only God means human rulers cannot displace His authority over the Sabbath by claiming to change His law. The Sabbath remains His binding memorial of creation, and rejecting it has serious consequences.

Trust, Study and Mission

The declaration that the Lord alone is God with none beside Him is a very full revelation of His purpose for His people and is to be prayerfully studied. It directs His people to seek wisdom from Him and not to turn away from His wisdom to look to finite man for wisdom. There is no other source of divine help, so they are to trust the Lord rather than depend on other powers or associations or any other supposed help. He alone is the only source of wisdom and salvation. Looking unto Him alone brings salvation to all the ends of the earth, blotting out of transgressions as a thick cloud, return and redemption of Jacob, righteousness and strength in the Lord, and justification and glory for all the seed of Israel. Every knee shall bow to Him and every tongue shall swear, all who were incensed against Him shall be ashamed, and heavens, earth, mountains and trees break into singing because the Lord has glorified Himself in Israel.

As He girded Cyrus though Cyrus did not know Him, God equips and directs persons for His purposes even when they do not know Him. Those carrying out His purposes are instruments in His hands and instruments of His power rather than the source of their own success. Divine power directs the work, with His guidance and the ministry of heavenly beings directing it. His servants should therefore trust Him and go forward rather than carry the burden as though success depended on themselves. From Him they receive the ability, wisdom and success needed for their work, and to Him they are to give the glory.

Because the Lord is God and before Him there is no other, honor is to be given to no human instrumentality but to God alone, that His name may be a praise in the earth. All advantages and means and facilities are His. His sole Godhead therefore requires unselfish imparting of what He has given to lighten darkened nations and new fields, rather than confining it to a few places at home or withholding it through selfishness and desire to control. The Lord God of heaven girds and uses His people even when they do not fully know Him, because His name can be glorified through them. That use calls for missionary work and a missionary spirit that carries His name into the highways and the hedges.

The verse stands among God's promises and covenant, showing what the Lord has done and what He will do for those who follow on to know Him. It gives encouragement to be appreciated and acted upon. It reveals the greatness of the love and compassion of God in pure, excellent language. It holds the loftiest themes of thought and gives elevating, ennobling principles to bring into daily life. It requires stretching the faculties of the mind to comprehend it.

It is better for students than romance or fable and should be made a valuable study and lesson book and put in form and brought into schools. It turns the life away from devotion to a world soon to be destroyed and toward heaven as home with citizenship above. It tells of the city being sought, whose Builder and Maker is God. The Word of God needs to be revealed in living characters. The wider passage of Isaiah 45:1-8 is a call from the Lord to awaken out of sleep. It shows that lack of love, patience, forbearance and confidence is most displeasing to God, and it calls believers, as those in Melbourne were called, to heed the messages God has given them and to open the door of their hearts to faith that works by love and sanctifies the soul.