This abbreviation is most often found in older cemeteries and originally stood for requiescat in pace in Latin. The direct translation in English is “rest in peace,” though the Latin words are actually part of a longer prayer for the deceased.
Requiem æternam dona ei, Domine
℟. Et lux perpetua luceat ei:
℣. Requiescat in pace.
℣. Eternal rest, grant unto him/her, O LORD,
℟. And let perpetual light shine upon him/her.
℣. May he/she rest in peace.
In the early centuries of Christianity the symbol was adopted by Christians and often used in Roman catacombs. It is believed that part of the inspiration came from the following passage from the Letter to the Hebrews:
We have this as a sure and steadfast anchor of the soul, a hope that enters into the inner shrine behind the curtain, where Jesus has gone as a forerunner on our behalf, having become a high priest for ever after the order of Melchiz′eek. (Hebrews 6:19-20)
Hope then became associated with the anchor, specifically the hope of salvation. This symbol was etched onto catacombs, along with such words as pax tecum, pax tibi, in pace, in Christian hope that the deceased would be anc****d in heaven.
Dating all the way back to the third century, Christians shortened the name of Jesus by only writing the first three letters of his name in Greek, ΙΗΣ (from his full name ΙΗΣΟΥΣ). The Greek letter Σ (sigma), is written in the Latin alphabet as an “S,” resulting in the monogram being commonly represented as ΙΗS.
On a gravestone, it simply denotes someone who was a Christian and proclaims their hope in eternal life.
A common symbol on gravestones, two clasped hands can represent many different things. It could mean a farewell to earthly life, a welcoming of heavenly life or a promise to living family members that they will be waiting for them in eternity. It could also simply mean friendship or represent the love the deceased person had for others.
A common symbol used in classical Christian art is the laurel wreath or crown. In the ancient world the crown signified many things, and Christianity adopted it to signify the crown that is awarded those who to go heaven.
On gravestones it signifies the person’s hope in heaven, that they too will be awarded that crown on account of the life they led.