Does Grace Save?

There is a book  "If Grace Is True, Why God Will Save Every Person." Authors are Philp Gulley and James Mulholland. a couple of Quaker ministers, whatever that entails. Also on the cover is a quote from Saint Augustine "There are many who though not denying the Holy Scriptures, do not believe in endless torments." The book is interesting but each of their points is supported by an 'I think' instead of a reference in the Bible. Similar to a lot of comments we hear in our Bible classes.
 
Assuming some will be saved and some will be lost, do we understand what that belief means? My question is: What does one have to believe to be saved and what does one have to do to be saved? Can they believe right and not do or can they not believe but do or does it take both?
 
Within the Church of Christ there are many 'views' on what is right and wrong. There are divisions between the instruments and non-instruments as well as divisions within the non-instrument group. Divisions to the point of refusing to acknowledge the other can be Christian. How can any be saved?
 
If we are going to disagree with Gulley and Mullholland it might be worthwhile to know where specifically we disagree and to know what defines saved? Is immersion the dividing line? When we go to the funeral of a person not associated with the Church of Christ do we in our hearts believe they are saved? If we believe they are lost but have not done everything possible to convince them otherwise can we possibly be saved? Does grace cover our misdeeds but not the misdeeds of others? Do we agree with Gulley and Mulholland but at the same time deny that we do?