If God has predestined everything to be as it is, and we are just living it out with the Holy Spirit guiding our way, to what degree will God allow us to sin? Where does “our” choice to do right and wrong fall?
God’s sovereignty over all things does not require that mankind be without the ability to make choices. Rather, God’s sovereignty ensures that the outcome of mankind’s decisions conforms to His will in the end. Therefore, mankind possesses a free will to make choices in defining the path in life, nevertheless God's will sets the destination for our path, so that in the end we remain accountable for the path we chose.
The New Testament teaches repeatedly of the need to set aside the desires of the flesh and to yield to the Spirit of God so that we might accomplish the will of God. For example, the following command in scripture would have no meaning if man’s will was not an issue in our walk of sanctification:
Scripture teaches that believers are responsible for how we follow the Lord, and our eternal rewards are determined by our track record of service. We are not left to accomplish this by ourselves, of course. The Spirit living inside us works in our heart through the ministry of God’s word to draw us closer to Christ, teaching us in ways of righteousness and convicting us of our sin. When we yield to the Spirit and discipline our flesh, we will walk in the counsel of God to please Him through our obedience. When we grieve the Spirit, we spurn the grace of God and rebel against Him.
Regardless of which path a believer chooses (i.e., obedience or disobedience), the Lord’s will concerning all things will be done in the end. Obviously, there is a degree of mystery involved in reconciling these two principles in scripture. We wonder how God’s will may be assured regardless of whether I choose to turn left or right? Somehow in the omniscience and omnipotence of God, our choices and decisions remain our own yet serve to accomplish God’s will in the end.
You may find the following article helpful: God's will vs Man's will
We also recommend you listen to Lesson 2C in our Ephesians study.