'Reliable' in the Bible

So Achish summoned David and said to him, "As surely as the Lord lives, you are an honest man, and I am glad to have you serving with me in the army. I have found no fault with you from the day that you first came to me until the present time. But in the opinion of the leaders, you are not reliable.

Achish replied to David, "I am convinced that you are as reliable as the angel of God! However, the leaders of the Philistines have said, 'He must not go up with us in the battle.'