What difference does God’s sovereignty make if we still have to work to make His will come true in my life and in the world? 
That’s the question that plagued me for several years. Ever since I became a Christian, the question of God’s sovereignty and man’s responsibility has been swirling around me. And I know it’s not just me. I get asked all the time by the young and old alike how God could be in absolute control of everything (sovereign) but we the human beings still have a choice in the matter. The question usually goes, “What does it matter what we do since in the end, God’s will be done anyway?” 
For example, if it is God’s will for those in a South American village to be saved, then they will be saved no matter what. There is no need to send them missionaries. So the argument goes. 
The human logic would dictate that. However, God’s sovereignty is such that God uses what we do as a means to bring about His will. He allows us and our actions to participate in His divine will for them to come true.
For example, when Mordecai, Esther’s uncle, challenges Esther to approach the king to save their people – the Jews – he says, “For if you keep silent at this time, relief and deliverance will rise for the Jews from another place…” (Esther 4:14) 
However, God’s sovereignty is such that His decreed will is an absolute guarantee. And that decreed will does include who gets saved and who does not. 
“All that the Father gives me will come to me, and whoever comes to me I will never cast out.” John 6:37So then, going back to the original question, “What difference does God’s sovereignty make if we still have to work to make His will come true in my life and in the world?” The answer is: It makes a difference in HOW we work if we knew the result ahead of time. 
For example, if you knew that in the end, you WILL be sanctified and reach perfection, you will not give up working on your sanctification. Whereas, if you weren’t guaranteed that end result – in other words, if you didn’t know whether you would ever reach perfection or not – you might give up! 
And those whom he predestined he also called, and those whom he called he also justified, and those whom he justified he also glorified. (Romans 8:30)

Keep working on your sanctification (to become like Christ) even if you fail again and again. You will get there. It depends on God’s sovereignty and not on you ultimately. 
PH