Do what I should do to honor the Lord

Kings 1:1-27
King David was old and well advanced in years, he not only can't want even they put covers keep him, he also didn't know what happen outside.
Adonijah wanted to be a king, he has prepared and invited his brothers and Joan, Abiathar the priest. He did not invite others who didn't support him and Solomon.
Nathan, the priest, advised Bathsheba how to save her life and the life of his son Solomon.
Bathsheba did as Nathan said, Nathan came in told David later to prove what her said and he asked King David "Is this something my lord the king has done without letting his servant know who should sit on the throne of my lord the king after him?"
Why?
His three elder brothers dead, Adonijah is heir apparent. But the throne has been promised to Adonijah's half-brother, Solomon(1 Chronicles 22:9)
Thanks to some quick thinking by the prophet Nathan and quicker action by the old king
This promise is not recorded elsewhere.
Nathan did a good job on his role- a priest, spoke for the Lord, reminded king David.
How?
To be a servant of the Lord, like Nathan, say when it time to say don't afraid other people. Do what I have to do. My lord is the God. Do what is good the Lord.