Paul didn't include "argumentative" in his list of the fruits of the Spirit, but Christians seem to add it from time to time, especially when it comes to non-believers. We are called to be the peacemakers, not conflict seekers.
Whether we are confronting sin, discussing interpretations of Scripture, or even the existence of God at all, we can get so fired up defending our stance that conversations turn into arguments. And in doing so, we misrepresent the very thing we are so passionately defending.
God has done plenty to prove His existence and has all the power to convict others of their sins and theological misunderstandings. He doesn't need our help. He asks us to show patience and kindness to others. This is how we represent the one thing He commanded repeatedly: His love.
