When Calvinists focus on whether something is or isn't God's will based on what happened when they prayed, it is a failure to understand that God's will often includes human involvement. We have a personal relationship with God through Jesus - and God wants to work in relationship with us to accomplish His will! Ananias in Acts 9 was just wanting God to sovereignly stop Saul without his involvement. But God wanted to work through him! God's way to accomplish his will can often involve more than a "if it be thy will" prayer!
The church many times sees healing ministry, witnessing, and Holy Spirit ministry as something for those with great character and good theology as some sort of reward for having been disciples. However, Jesus picked people with major character flaws (like Judas, Peter, James, and John) in Luke 9:1-2 to be empowered and saw Holy Spirit ministry as one more aspect of their discipleship process.
If you take too much credit for what God does through you, it can create an orphan spirit where you depend too much on your resources instead of His!