Read 1 Samuel 17:26
Then David spoke to the men who stood by him, saying, "What shall be done for the man who kills this Philistine and takes away the reproach from Israel? For who is this uncircumcised Philistine, that he should defy the armies of the living God?"
When my son, Tim, was about 14 years old, we were visiting my mother and father in western Pennsylvania. My father was outside on a ladder washing an upstairs window. Tim opened the window, stuck his head out and said, "Whatcha doin', old man?" If there's one thing you never said to my father, you never called him "old man." He thought that was disrespectful. So what did he do? My father turned the hose on Tim! My son never forgot that lesson.
David felt the same way about the challenge issued by Goliath. The nine-foot-tall champion of the Philistines was not just making Saul's armies look cowardly for refusing to respond to his harassment; Goliath was showing disrespect toward the living God. When the Philistines taunted the armies of Israel, they were mocking the God of Israel as well. By throwing insults at Israel, they were implying that God was also weak and ineffectual. This was something David couldn't tolerate.
Our own honor is insignificant. When people do not show us the respect that perhaps they should, it matters little. God ultimately will make up for such oversights (Rom. 8:16-19). But when God's character is called into question, that's a different issue. When God is ridiculed or belittled, it is the duty of every Christian to object, whether we do so privately or publicly. We should never ignore those who dishonor God.
Do not be afraid to defend God's honor. God will sustain you if you are willing to take a stand for Him. Whether it is in the workplace, in the university classroom or in a social setting, let others know that God deserves their respect.
Honor God and He will honor you.