2 Samuel 20:15-22 ...While they were battering the wall to bring it down,  a wise woman called from the city, “Listen! Listen! Tell Joab to come here so I can speak to him.” ... [(21c) Joab replied] Hand over this one man, and I’ll withdraw from the city.” The woman said to Joab, “His head will be thrown to you from the wall.”  Then the woman went to all the people with her wise advice, and they cut off the head of Sheba son of Bicri and threw it to Joab. So he sounded the trumpet, and his men dispersed from the city, each returning to his home. And Joab went back to the king in Jerusalem.
•• Pretty gruesome! But the key point for us today is the amazing power of one believer.
• All we know of her is that she was a “wise woman.” Her good advice single-handedly saved a city.
• One piece of “wise advice” (22) can change history.
• In 1971 an elderly Christian woman in Anchorage gave me some “wise advice” that headed me off from making a very unwise career decision.
• On the negative side: [Eve] “Go ahead, Adam, it tastes good, and the serpent said it will make us wise.” Bad advice can likewise change history!
•• Your decisions — and your advice to others — can start a cascade of events that can affect literally thousands. One believer has amazing power — for good or for evil.
1 Samuel 17:32-33David said to Saul, “Let no one lose heart on account of this Philistine; your servant will go and fight him.”  Saul replied, “You are not able to go out against this Philistine and fight him; you are only a boy, and he has been a fighting man from his youth” ...  David said to the Philistine [Goliath], “You come against me with sword and spear and javelin, but I come against you IN THE NAME OF THE LORD ALMIGHTY, the God of the armies of Israel, whom you have defied.  This day the LORD will hand you over to me...  for the battle is the LORD’s, and he will give all of you into our hands” ... [49b] The stone sank into his forehead, and he fell facedown on the ground. [caps mine]
•• David’s defeat of Goliath turned the tide of history for Israel. “But...but...but...”
• King Saul protested that David was “only a boy”! (33)
• He was a shepherd, not a trained fighting man.
• The opponent was seemingly invincible: a 9-foot giant
• Do dwell on the reason you will win — “the name of the Lord Almighty.”
2 Timothy 1:15-17 You know that everyone in the province of Asia has deserted me, including Phygelus and Hermogenes.  May the Lord show mercy to the household of Onesiphorus [which means “help-bringer”], because he often refreshed me and was not ashamed of my chains.  On the contrary, when he was in Rome, he searched hard for me until he found me.
•• Onesiphorus, who often refreshed imprisoned Paul
• Other believers deserted Paul in his Roman cell.
• Contrariwise, Onesiphorus searched hard for him.
• Other believers “were ashamed of [his] chains.”
• Onesiphorus openly sought out Paul in his chains.
•• One believer's actions can change history.
• Paul was refreshed by one man. And he wrote this epistle from that refreshed state in prison!
• The amazing power of one “help-bringer”!
• You help or refresh one person, and he or she may be encouraged to do something great for God.
• The child you encourage in Sunday School may be the next Billy Graham.
• The child you raise in the faith while you are married to an unbelieving husband may become the next Timothy.
• The kind word you share may be the catalyst to turn a backslider’s life around.
Acts 9:9-12, 17-18  In Damascus there was a disciple named Ananias. The Lord called to him in a vision, “Ananias!” “Yes, Lord,” he answered.  The Lord told him, “Go to the house of Judas on Straight Street and ask for a man from Tarsus named Saul, for he is praying.  In a vision he has seen a man named Ananias come and place his hands on him to restore his sight” ...  Then Ananias went to the house and entered it. Placing his hands on Saul, he said, “Brother Saul, the Lord — Jesus, who appeared to you on the road as you were coming here — has sent me so that you may see again and be filled with the Holy Spirit.”  Immediately, something like scales fell from Saul’s eyes, and he could see again.
•• Ananias: simply a “disciple (10) ... a devout man” (Acts 22:12, KJV)
• One man, otherwise unknown
• But God used him to heal Paul's blindness and to launch a world-changing ministry!
•• The key?  “The Lord called to him.”
• Listen for that “still, small voice.”
• Listen for His instructions as you read His Word.
• And as the Lord “calls to” you, you can heal the sick, raise the dead, cast out devils...
Many fine sermons are preached on the authority of the believer, often very properly keying on verses like Luke 10:19 — "I have given you authority ... to overcome all the power of the enemy." Unfortunately, many of those messages do not proceed to speak of God's power manifested through the believer in life-changing ways.
The battle is the Lord’s, not ours. Look past the natural ... listen for God’s leading ... obey in Jesus’ name ... and you will experience the awesome power of one believer willing to follow the Lord.