Summary: God is sovereign! The message explores what this means in the life of the believer.
“To the King of the ages, immortal, invisible, the only God, be honor and glory forever and ever. Amen.” 
The Apostle, writing to his son in the ministry, has just expressed gratitude to God, marvelling that he received appointment to divine service, especially in light of his former life. God had assuredly demonstrated mercy and grace toward the rebel, and that resulted in marvel and wonder at the grace Paul had received. The Apostle is quite clear on the reason he received such mercy—it was so that he might serve as an example of God’s patience, of His mercy and of His grace. By his appointment, Paul would draw outsiders to consider life in the Beloved Son and believers would be encouraged in their walk with the Master.
Concluding exclamation of wonder and admiration, the Apostle breaks forth in joyous exultation. “To the King of the ages, immortal, invisible, the only God, be honor and glory forever and ever. Amen” [1 TIMOTHY 1:17]. This one statement of praise contains a wealth of information begging exploration by those who know the True and Living God.
GOD’S SOVEREIGNTY DECLARED — “To the King of the ages…” Paul ascribes this unique title to the Lord God. The closest I can come to seeing this title applied to the Lord God elsewhere in the Word is when the Tribulation Saints sing The Song of Moses as recorded in the Apocalypse.
“Great and marvelous are your deeds,
Lord God Almighty.
Just and true are your ways,
King of the ages.”
[REVELATION 15:3 NIV (1984)] 
There is some dispute over whether the final ascription should be to “King of the ages” or to “King of the nations.” A few older manuscripts do ascribe the song as being sung to Him who is “King of the ages,” but the preponderance of evidence is that John wrote the ascription to Him who is “King of the nations.” What is important is to note that on the whole, Paul provides us with a unique means of identifying the True and Living God. As an aside, it is perhaps of interest to note that the newer editions of the New International Version align with other translations in ascribing the praise of the Tribulation Saints to the “King of the nations.” 
However, though the original reading provided in the Revelation continues in doubt, Paul’s identifier is by no means out of line with what we are taught in the Word concerning the Lord our God. Throughout the Word, God’s position as King is stated and accepted as settled. God is eternal; He is also sovereign over all that He has created. Establish in your mind that when we speak of God’s sovereignty, we have in mind His power. In theological terms, we are referring to His omnipotence. It means that God can do as He wills.
Various attributes belong to God because He is God, but when we speak of His sovereignty we are identifying the one characteristic assuring us that God is Ruler of all things. Whenever we speak of God’s power and might, we are acknowledging that there are no external constraints on His decisions. Thus, the fact that God is All Mighty, or Omnipotent, means that He possesses power to do whatever He wills.