As a kid, I experienced "Christianity" in various settings including fundamentalism, mainline denominations, cults, and fringe charismatic churches. God used these experiences to give me a passion for theology, a desire to know him with certainty and precision.
As an ever-maturing believer, I continue to learn and experience God's truth and God's grace each day. Through this grace, I was able to escape the influence of the bad theology of my childhood, but what God used was not only a new set of beliefs, but people and friends and teachers and other students who lovingly and very pastorally communicated these truths, showing me why they ultimately mattered.
Defending the faith and promoting solid theology ought to be in a spirit of love and truth. The motivation should not be rightness for its own sake, but for the cause of Christ--a genuine love for people. God's love and God's truth go hand in hand and should never be divorced from each other.