Truth has its own persuasive power, because Jesus Christ is the Truth.  Truth is embedded in the character of God.  Unlike the Greek philosophers of Paul’s day, who aggressively argued their convictions, God’s servants had no need to do that.  Teaching the gospel and disciplining believers is not a personal contest; it is the unveiling of God’s mind and heart through the Scriptures by believers who are willing to lay down their rights and even their lives to share the gospel (2 Corinthians 4:5-11).  A true response cannot be forced.  Those who recognise the truth and want to obey it, will receive it.  Oratorical trickery is unnecessary (1 Corinthians 2:1-5).  

But Paul was certainly willing to argue the Jesus is the Son of God - crucified for our sins and raised for our justification (Romans 4:25).  He presented the gospel clearly and was willing to persuade people of its truth (Acts 19:8; Acts 28:23-24).  The issue here is not whether the gospel should be presented persuasively, but what is the motive and attitude of the presenter.  The arrogance of the 2stC orator had no place in gospel presentation.    
 
Timothy needed to be encouraged that he could instruct the ignorant gently as Jesus did (Matthew 11:29), being sensitive to their spiritual disability (1 Thessalonians 2:7).  Those who showed fierce opposition must be treated patiently – for that is a manifestation of love (1 Corinthians 13:4).  He should expect opposition but should also realise that the hostility was not against him; they were rejecting God.  He should still teach any who would listen, hoping and praying that God would change their hearts and that sinners would be released from Satan’s grip (Hebrews 2:14-15), and be set free to love and serve the Lord.
 
Many believers are too frightened to speak about Jesus.  They think that they may be beaten down by arguments which they cannot answer.  Some teachers are happy in their pulpits but reluctant to dialogue with people who are seeking truth.  However it is good for people to ask questions – as children do.  When God’s Word is presented clearly, it has its own internal power (Hebrews 4:12-14) to convince people’s hearts.  St Augustine said, ‘The truth is like a lion. You do not have to defend it. Let it loose. It will defend itself’.  So be kind and tell the truth clearly, confident that the Lord is doing His work through you … but it is still His work for His glory and not ours.