'Truthfully' in the Bible

and so that the LORD may fulfill his promise that he spoke about me when he said, "If your sons pay attention to how they live by walking truthfully in my presence with all their heart and with all their soul, you will never lack a man on the throne of Israel.'

"You have demonstrated abundant gracious love to your servant David, my father, as he lived in your presence truthfully, righteously, and uprightly in his heart. In addition, you have kept on showing this abundant gracious love by giving him a son to sit on his throne today. Now, LORD my God, you have set me as king to replace my father David, but I'm still young. I don't have any leadership skills.