There are many who claim that Christians just simply need to "do good deeds" and downplay or ignore doctrine.
Evidently, Dr. D. Martyn Lloyd-Jones, one of the greatest preachers of the century just past, did not agree:
There are many today who regard truth and error as matters of small consequence; if a man lives rightly, they say, it matters not much what his beliefs and opinions are. Such statements do not surprise us. Night and day are all one to a blind man. Truth and error are all one to an ignorant man.(HT: e- mail brigade news)