1st Kings 1:6 And his father had not displeased him at any time in saying, Why hast thou done so? and he also was a very goodly man; and his mother bare him after Absalom. 7 And he conferred with Joab the son of Zeruiah, and with Abiathar the priest: and they following Adonijah helped him.
[Patriarchs & Prophets pp 749] In his youth he had been subjected to but little restraint; for “his father had not displeased him at any time in saying, Why hast thou done so?” He now rebelled against the authority of God, who had appointed Solomon to the throne. Both by natural endowments and religious character Solomon was better qualified than his elder brother to become ruler of Israel; yet although the choice of God had been clearly indicated, Adonijah did not fail to find sympathizers.
Joab, though guilty of many crimes, had heretofore been loyal to the throne; but he now joined the conspiracy against Solomon, as did also Abiathar the priest. The rebellion was ripe; the conspirators had assembled at a great feast just without the city to proclaim Adonijah king, when their plans were thwarted by the prompt action of a few faithful persons, chief among whom were Zadok the priest, Nathan the prophet, and Bathsheba the mother of Solomon.
They represented the state of affairs to the king, reminding him of the divine direction that Solomon should succeed to the throne. David at once abdicated in favor of Solomon, who was immediately anointed and proclaimed king. The conspiracy was crushed. Its chief actors had incurred the penalty of death. Abiathar's life was spared, out of respect to his office and his former fidelity to David; but he was degraded from the office of high priest, which passed to the line of Zadok.
1st Kings 2:27 So Solomon thrust out Abiathar from being priest unto the Lord; that he might fulfill the word of the Lord, which he spake concerning the house of Eli in Shiloh.
May God add His blessing to the study of His word. “Good night” and God bless!