I would never downplay the role of the mind in Christianity. It is part of the most important commandment
Matthew 22:36-38 (NIV)
36 “Teacher, which is the greatest commandment in the Law?” 37 Jesus replied: “‘Love the Lord your God with all your heart and with all your soul and with all your MIND.’ 38 This is the first and greatest commandment.
But the mental aspect of apologetics isn’t as important as living as a Christian. It doesn’t matter one bit how intelligent your words are if you are living like the devil. There are way to many people out there who say they are Christian, and turn around and commit terrible crimes! Most infamously people like David Koresh, who claimed to be a Christian for most of his “ministry” but later claimed to be Christ himself, and priest who were overly fond of little boys. But there are a lot of people who claim to be Christian with their mouths, but live in ways that completely contradict the word of God. If you are mean, and nasty in one breath, and in the very next talk about the love of God, no one will listen to you. SOME of the things the Rev. Phelps guy says are technically correct but his behavior is so vile that any somewhat decent person who hears him speak will reject everything he says.
Always keep in mind that any time you identify yourself as a Christian people will be watching your conduct. They see you as a reflection of our God. If you act like a jerk, or commit newsworthy crimes this reflects poorly on Christ.
The closer you live to God’s word, the more believable your words about God will be.