5. The Goal Is The Gospel
At the end of day, your goal should not be to win the argument and seem smarter. Your goal should always be to point that person in the direction of Christ. If the purpose of your discussion is to outsmart the other person or show them how much better you are for being a Christian, then I can tell you this from experience: repent, God is coming soon to outsmart you.
Man is broken and eternally separated from God without the bridge that Christ built by His sacrifice and resurrection. You can get someone to believe what you believe politically, morally, ethically, and even somewhat spiritually. But if they do not have the saving knowledge of our Lord Jesus Christ, to what avail were your efforts?
In summation, we are called to defend our faith and always be prepared to give an answer (1 Peter 3:15). We are also called to turn the world upside down as the first century apostles did. Instead, we as Christian are constantly playing the retreat game and hoping that the next person we talk to is either a Christian or an ignorant non-Christian.
Is that the manifestation of the Spirit of God inside of you? Cowardice? Ignorance? Silence?
