It's Not Easy Being a Cleric
The cleric is a party member in role-playing games responsible for healing everyone. As a class, it has its fair share of stigmas. There are many types of clerics you can be, but more often than not, you are only allowed to deal the healing and can only attack or do anything else when everyone is okay. Sometimes it's disheartening that people only want to keep you alive so they can keep themselves alive.
Clerics don't get group heal spells until higher levels. This means that lower-level clerics use up more of their spell slots on everyone individually; once they're gone, they're gone until after a rest period. There are healing potions that every party member should have purchased before the adventure began to have on hand while they wait their turn for the cleric to get to them, but more often than not they forget and just start yelling for help. They only tend to remember if the cleric goes down and they need to shove one down her throat to keep her from dying.
Clerics tend to put most of their points into the stats that boost their magic abilities, strength not being one of them (although there is such a thing as a battle cleric). Therefore, it is foolhardy for a cleric to try to do any type of physical attack or contribute to a battle in any way other than magic, which is usually going to be heal spells or other spells that benefit the party. There is nothing more frustrating for a cleric than to want to join in a fight but only be fit to restore health and hit points to as many people on the team as possible. There are spells that deal damage to foes, but in the heat of battle, you have to make a decision whether to help a party member by healing him or by making a dent in the enemy's hit points.
Sometimes a cleric can feel like a utility player if all anyone does is ask for healing all the time. A character's backstory can be that they travel the world helping and healing people, but some people, especially other player characters, will take advantage of that. That's why you have to play with a group that values you as a person before anything else (even though they will forget once they get into character). Usually, no one wants to be the cleric, but they still want one on call. A character will not be respected until they have gained some levels and notoriety, but that is no excuse for treating them like just another tool. Clerics certainly aren't the only ones with heal spells, but they are a class largely built around them.
In summation, just because a cleric is the designated healer, it doesn't mean that's all they're good for. While they don't need a D20 to use heals on themselves or their party members, each roll for magic or normal attacks is just as likely as anyone else's to roll a hit or a miss. While it makes sense to keep a cleric alive for their healing powers, it would be nice if every once in a while someone said they were keeping them alive for who they are instead of what they could do or had done lately.
Battle Cleric: At least they can LOOK menacing!
Cleric: I come bearing the word of my god. That word is "Begone!"