Abner’s move to David is most likely driven by politics and not by theology.1 Though he made mention of the Lord, his actions had more to do with the offence caused by Ish-bosheth’s accusation than a conviction that he was wrong to support Saul’s son as king. He may have also considered that Ish-bosheth was certain to lose the fight2
9 Que Dieu traite Abner dans toute sa rigueur, si je n'agis pas avec David selon ce que l'Eternel a juré à David,