I need to raise something difficult with my pastor and I have been putting it off for months. How do I actually do it?

“And Nathan said to David, Thou art the man. Thus saith the LORD God of Israel, I anointed thee king over Israel, and I delivered thee out of the hand of Saul;”

Nathan had to confront the king who could have had him executed, about the worst thing that king had ever done. He does not open with the accusation. He tells a story, lets David pass judgment on it, and only then names him. Nathan went, he went carefully, and he went with the truth completely intact. Courage and skill were both required of him, and both of them can be learned.

“But when Peter was come to Antioch, I withstood him to the face, because he was to be blamed.”

Paul describes confronting Peter, the most senior figure in the early church, because Peter's behavior toward Gentile believers contradicted the gospel he preached. Paul puts it in a letter without triumph and without apology. The New Testament does not treat leaders as beyond correction, and it does not treat correction as disloyalty. What it does assume, every time, is that you go to the person rather than around them.