If you’re preaching, you are the messenger. And if your passage is saying “hard things” you – as the preacher – can feel like you’ve got to be the messenger of these hard words.
But that’s not the best way to go about it. Partly because people will simply dismiss YOU. Once they decide you’re a jerk or that you’re too young to know or anything like that, they have “shot the messenger” and have no reason to listen to the message. But the primary reason you shouldn’t make yourself the sole messenger is because you’re getting in the way of God speaking from his Word.
The “harder” the message, the more you need to show people that it’s not your message, its the bible. Keep pointing them to it. Say things like, “Look at verse 3 again… verse 3…”, “Read these words with me in your head…”, “This is not me saying this, this is the bible speaking”.
And once you start seeing how important this is with “hard things” in the bible, the more you realise you should do the same for “all things” in the bible.