1 Samuel 17:55
And when Saul saw David go forth against the Philistine, he said unto Abner, the captain of the host, Abner, whose son is this youth? And Abner said, As thy soul liveth, O king, I cannot tell. And when Saul saw David go forth against the Philistine, he said unto Abner, the captain of the host, Abner, whose son is this youth? And Abner said, As thy soul liveth, O king, I cannot tell.
The moment captures Saul watching the youth go forth against the Philistine. In that setting the king would have had David place his confidence in armor supplied for the fight. David would not place his trust in it, but laid aside the royal armor because it was untried and unproved to him. Instead he trusted in the God of Israel and made God his strength.
By contrast Goliath trusted in his own armor, coming out confident and boastful, defying his opponent and magnifying himself. Ministers who defy and provoke discussion and then rely on their prepared arguments act the part of Goliath and repeat Saul's armor. They fail to hide behind Jesus and to humble their hearts in faith so that God Himself gives the victory to the truth. Their discussions do not succeed, but injure their own souls and the souls of others.