You don’t ever have to choose between being a “love” person or a “truth” person. It shouldn’t be a tradeoff. In fact, we should think that growing in both love and truth is a part of Christian discipleship.
But what does John mean by walking in the truth? According to this book and the other books by Joh, it is clear that for him, walking in the truth means to live according to the truth of the message of the gospel.
The calling from the Bible is that we be constantly aware and on watch as deceivers, false teachers and distorters of the truth will always be there. The price of living in the truth is eternal vigilance.