The first and most important part of critical thinking is to have the Spirit of God.  Jesus said that the Spirit of God is the Spirit of truth: “When the Helper comes, whom I will send to you from the Father, that is the Spirit of truth, who proceeds from the Father, He will bear witness of Me," (John 15:26).  Truth is what conforms to reality.  We we can argue all we want about what is and is not true, but we as Christians should make sure that the truth that we are trying to establish is not done with malice and anger.  "But the goal of our instruction is love from a pure heart and a good conscience and a sincere faith," (1 Tim. 1:5).  Also, "Let your speech always be with grace, seasoned, as it were, with salt, so that you may know how you should respond to each person," (Col. 4:6).
     We must be careful not to win an argument for the sake of trying to win an argument.  If we are rude and arrogant in our discussion, even though we may win the argument, we lose the person.  This is why humility is a very important part of critical thinking; actually, is an important part of displaying our critical thinking.  You see, if you are humble in your presentation, admit when you don't know something, admit when you are wrong about something, etc., it adds far more credibility to you than you might realize.  People do not want to be bullied into believing or belittled.  If your approach in witnessing and defending the faith is done with arrogance and sarcasm, then you should not be involved dialogue in the first place.  A common danger when "out thinking" someone who is opposing the gospel, is to become prideful and self-confident.  We need to be very careful of this.
     Pride and humility are similar.  Both hide themselves in the person so that the person does not see he has them, but others do.
     So, the first thing you need to do is to get right with God, confess your sins, and ask God to work humility in you.  Second, desire to present your position with humility and love and ask God to help you do this.  Nevertheless, though we may seek humility in our defense and establishment of truth, even the best of us make mistakes and sometimes become prideful.  When this occurs, it is best to confess our sins, apologize to the one we have offended, and continue to do your best to present the truth of God's Word.  This is how we learn and this is how we improve.
     Jesus said that out of the abundance of a heart the mouth speaks (Matt. 12:34).  If what is in you is pride and arrogance, then that is what will come out.  But, if what is in you is the Spirit of God and humility, then that will come out as well and often times humility, love, and patience are the absolute best witnesses, often overcoming our lack of critical thinking skills.
    

"Do nothing from selfishness or empty conceit, but with humility of mind let each of you regard one another as more important than himself," (Phil. 2:3).