First of all “liberal” has a lot of meanings. I can mean “free” is in the Liberal Arts which are free from the constraints of censorship. Classical Liberal political theory argued for freedom of the individual. 20th Century “Liberal” on the other hand means something like “progressive” and views government as the main agent of liberty. Theologically Liberal comes from the early 20th Century conflict between Modernists and Fundamentalists. Modernists went to be called Liberals and now Progressives and Fundamentalists divided between those who like that term and those who prefer Evangelical and often now simply “Jesus Follower.”
My friend meant “theologically liberal” I suppose. There are some attempts to translate the scriptures in a totally gender neutral way. Someone heard in a church liturgy that the Lord’s Prayer began with “Our Leader” instead of “Our Father”. So some wish to do away with Trinitarian language of Father, Son and Holy Spirit, because of the latent “paternalism” of “Father” and “Son”. Yet we have to say that Father does mean something different than leader or parent. Son is different than child and these words bear some theological weight. These sorts of translations are a kind of re-definition or revision of the scriptures according to an external cultural value (gender egalitarianism).
Yet the New NIV (NNIV) does not go that far. It merely attempts to say generically in English what is understood to be generic in the original context. So Romans 12:1 says “I urge you, therefore, brothers….” Since we do not think that Romans 12 only applies to male believers, the NNIV changes “brothers” to “brothers and sisters”. This really comes down to a preference in translation philosophy. Should the translation stick closer to the orignal words and it is up to the reader to understand the nuances? Or, should the translation spell out the nuances for the reader?
Also, in the 21st Century, generic usage has won out over using male gender for generic settings. We say “humankind” not “mankind”. We sing “Good Christians all rejoice” not “Good Christian men rejoice”. We do not say “The sinfulness of Man”, but “the sinfulness of humanity.” A theologically liberal “translation” might speak of the innate goodness of humanity. I once heard s speaker say “I don’t believe in original sin, but original goodness.” That, I would agree, reflects a theologically liberal viewpoint. but saying “humanity” instead of “man” or “mankind” does not.
So, the NNIV is not “liberal” in the sense that my friend asked. It may not be to his taste, but let’s be careful what we mean when we speak. It is moderately inclusive.