1 Corinthians 16:9
For a great door and effectual is opened unto me, and [there are] many adversaries.
Note 3 at 1Co 16:9: Paul's statement here is contrary to the beliefs of many Christians today. Most people expect "smooth sailing" when they are in the will of God. In fact, adversity is "proof" to most that they have missed God's will. That was not the way Paul looked at things.
Paul was saying that the Lord had given him a great opportunity to share the Gospel in Ephesus, but there was much opposition. He had just mentioned fighting with "beasts" at Ephesus (see note 4 at 1Co 15:32), and the book of Acts records that he was eventually "run out of town," nearly losing his life (Ac 19:23-20:1). In Ac 16:9, Paul was directed by the Lord in a vision to preach in Macedonia, yet within just a matter of hours after he arrived there, he was in stocks in the lowest part of the prison. Most people would have thought they had missed God.
By example, Scripture would come closer to teaching opposition, instead of harmony, as being an indication of God's will. However, neither of these extremes is correct. Circumstances are not a good test of God's direction. We need to depend on God's Word generally, and the voice of the Holy Spirit specifically, as our guide. Once we are assured through these, we should persist regardless of circumstances.