As King David lay on his deathbed, his oldest surviving son plotted to make himself the next king. He hired messengers. He consulted with leaders. He formed alliances. He hatched plots. Finally, he threw a great feast to celebrate his ascent to the throne, inviting most of the leaders and all of his brothers except one: Solomon.
Solomon, as far as we know, did nothing to advance himself. If he knew that his life was in danger, he did not do anything that we know of to protect himself. Meanwhile, Nathan the prophet told the aged King David what was happening. He reminded David of David's word, and God's Word, that Solomon would be the next king. David quickly had his loyal servants and leaders publicly anoint Solomon as king, and the people, loyal to their beloved King David, eagerly accepted Solomon.
Hearing the news, Adonijah's loyal followers quickly fled for their lives, leaving Adonijah to plead with Solomon not to kill him. With no known plots or schemes, Solomon had become king.
Christians sometimes hurt themselves by plotting to gain positions of leadership in the church. When they do succeed in backstabbing their way to the top, they often find themselves unable to handle the job, because God isn't with them. More than one successful rebel has watched the congregation dwindle as God led His people to go elsewhere.
Adonijah was definitely a man of ability, who might have gone far if he had obeyed God. He later tried another plot to become king, and this time, Solomon killed him. It is God's responsibility to raise up leaders of His people, not yours. Fear God, obey His commands, and serve Him. After that, it is God's responsibility to decide where to use you.