Why Kiss the Ring of the Bishop or Pope?

Question: Why do people kiss the Pope's ring when they are introduced to him? Why does he allow his hand to be grabbed and kissed? I noticed that Catholics also kiss the ring of Cardinals and Bishops. Can you please explain this? 

Answer: Since the early days of the catholic Church, the faithful have always kneeled and kissed the ring of the Church authorities. This traditional courtesy reflects the beliefs that:

i. the Pope who is the apostolic successor of the Church instituted by Jesus on earth;

ii. the Cardinals who are Princes of the Church; and

iii. the Bishops who are the local Shepherds of the Church, appointed by the Pope himself,

They are all priests through who Jesus Christ manifest Himself to lead His Church. By kneeling before these Christ chosen representives and kissing their rings, (the symbol of authority), one acknowledges their appointments by Christ Himself and show respect to Jesus who dwells in them. 

When kneeling is not possible, a bow to kiss the ring is acceptable. 

Why Kiss the Ring?

Most importantly, it should be noted that the ring being kissed is the Episcopal Ring.

For the faithful who devoutly kiss a prelate's ring, they are granted an associated indulgence.  

Kissing the ring of the Holy Father, they earn an indulgence of 300 days. 

Kissing the ring of a cardinal: an indulgence of 100 days

Kissing the ring of a patriarch, archbishop, or bishop, or prefect apostolic: an indulgence of 50 days. 

It is never improper to kiss the episcopal ring and the Pope and bishops will not refuse if asked for this blessing.

Therefore we often see in particular that many when meeting the pope, reach out to grab the Pope's hand and kiss his ring and the Pope does not withdraw or refuse his hand.

It also should be noted that if you are going out to grab a bishop's or the pope's hand for this indulgence, the gesture is symbolic and you do not need to 'smack you lips' squarely onto the ring itself.

There are many who mistakingly end up kissing the Pope's or bishop's hands instead. This may be done for other reasons of respect but it is not related to the kissing of the ring for a partial indulgence. 

It is also proper protocol when meeting the Pope to genuflect and to kiss his ring.This is repeated when taking leave of the Pope. 

Under strict protocol rules, when genuflecting (bending down with one knee) to the Pope, Cardinal or Bishop, the left knee is used. Genuflecting with the right knee is reserved for God. If genuflecting is not possible, a bow is acceptable.