Should Christians use the phrase Rest in Peace?

When reading through the death columns of a newspaper it is common to find the phrase 'Rest in Peace' or RIP at the end of some of the entries. It can be seen on gravestones, occasionally as a newspaper headline when a celebrity died and now frequently on social media when showing our sympathy. Whilst the phrase has been traditionally associated with purely Roman Catholic epitaphs it is now not uncommon for professing Christians to also use it. What then are the origins of 'Rest in Peace', what does it mean, and is it a suitable statement for a Christian to use on the occasion of a death?