So before we start I think this deserves some explanation. This has a lot of talk of religion in it so beware. Nothing derogatory, just simple talk. Please don't hate me for this. Don't read this if you think it'll offend you in any way.

I got the idea for this when I was rewatching episode one of Merlin. At one point in that episode Arthur says "Lord have mercy" when he sees Morgana at the feast. When I first watched the show I took this to mean that hey, Christianity was a thing during this show and that they were saying that in their canon King Arthur will be a Christian. Obviously I knew this wasn't going to mean anything very important to the plot. I just found this little bit of character information interesting. So I was even more curious that as the show went on everyone started mentioning the old Religion more as an actual religion instead of as magic or a driving force. Historically, King Arthur would have been around during the time when Christianity was becoming the major religion in the British Isles. This had to do with the withdrawal of Roman troops and the left over Christians kind of taking over the Celtic and Druidic holidays. I figured that royalty would be the most likely to practice this religion and I wondered what Merlin would do when confronted with it. Also - on the Merlin wiki page it implied that the Old Religion was replaced with the New Religion by Uther Pendragon. It's never mentioned what the "New Religion" is, so I'm taking liberties and making it Christianity.

Sorry that was long. I just felt the need to explain myself. I hope you enjoy this. And don't worry; The Return's next chapter is almost ready. I'm trying to make it longer for y'all.

Disclaimer: I don't own Merlin.

On with the story!

Please, God, Merlin thought desperately. Please let him live.

Merlin was seated next to Arthur's bed, listening to his labored breathing, trying not imagine that each breath would be the prince's last. Merlin was exhausted, but he wouldn't let himself sleep until Gaius was awake or he knew Arthur was going to survive. Whichever came first.

Merlin knew he was doing himself no good worrying. So he decided to do one better. Pray.

Merlin bowed his head and made the Sign of the Cross. Our Father, who art in Heaven, hallowed be thy name...

…

"You have Sunday morning off," Arthur said as Merlin brought him his dinner.

"Why, sire?" Merlin asked, and then cursed himself. He should look a gift horse in the mouth, not question it. Merlin had been working for the Prince of Camelot for almost a week now and it was obvious to him that working for Arthur was going to be a challenge, destiny or not. So far, the prince had struck Merlin as being arrogant, pompous, selfish and an all-around clotpole.

"All the servants have Sunday morning off," the prince said, looking at Merlin like he was an idiot for not knowing why.

"I understood that, sire," Merlin sassed. "I was just wondering why that is." Merlin crossed the room to Arthur's bed to turn it down for the night.

"For Mass, Merlin," Arthur said with a roll of his eyes.

Now Merlin understood. "Ah. Mass. Right," he muttered.

"I assume you'll be there," Arthur stated.

"Uh- no, actually, sire," Merlin said uncomfortably. "I'm not Christian. We didn't have a priest in my village and Christianity was not the dominant religion."

Arthur was silent for a moment. "Come anyway," he practically ordered. "You may find that you enjoy it."

Merlin stood by the table. "Yes," he said. "Maybe."

After Merlin was dismissed from Arthur's chambers he considered going to ask someone about this Christianity thing. But who would he ask? He decided on Gaius. After all, the old man was his guardian and knew a lot about everything, it seemed. Plus, the physician was unlikely to judge him.

"Gaius?" Merlin asked as he was eating.

"Yes, Merlin?" Gaius didn't look up from his book.

"Can you explain Christianity to me?"

Gaius looked up. "Where'd this interest come from?"

Merlin hesitated for a second. Should he really go through with this? "Arthur told me that everyone has Sunday morning off and then told me to go to Mass. We didn't have this religion, or any religion really, back in Ealdor. I was wondering what it was. Do you follow it?"

Gaius shut his book. "Yes, Merlin, I do follow the religion. Not as closely as I should, but yes, I do. Settle in, this is a long story." Merlin shoved some bread in his mouth and listened intently to Gaius. *

The next morning Merlin woke bright and early. He was exhausted. He and Gaius had been up late into the night asking and answering questions respectively. Merlin went to bed more confused than enlightened, but after a night of careful deliberation, decided he would give religion a try. After all, it seemed like something Arthur respected, so Merlin thought he might as well.

Merlin changed out of his nightclothes and pulled his boots on. He traipsed down the stairs outside his room. He grabbed a piece of cheese and a slice of bread then went over to where Gaius was working on a potion.

"Ah, Merlin," Gaius said. "Glad to see you are awake. I wasn't sure if you would be joining us."

"I decided to give it a try," Merlin responded.

"Let's go, then," Gaius said. "Mass starts on the hour."

Gaius led the way through the castle to the church. They joined a throng of people, with the king, Arthur and Morgana leading the way, that was heading the same way they were. Mass-goers, Merlin supposed. Soon they came upon a set of giant wooden doors set into the west wall of the square. As they entered Merlin turned his head to get a better view of the place. It was massive. There were easily a hundred rows of wooden benches that looked uncomfortable to sit on. Merlin's backside would not thank him later. Above their heads was a domed ceiling, painted with pictures that Gaius said were from the Bible. Merlin had ever seen or read a Bible before, so he just took Gaius at his word. The walls were marble and stone, like the rest of the castle, but unlike the rest of the castle, there were stained glass windows set into the walls. Each window had a different image of a person. Gaius said that each window represented a different saint. Far ahead of them was a raised marble platform. On it was a large stone table. Surrounding the platform was a marble rail, which Gaius called the communion rail. On almost every other surface there was gold. The morning sun was shining through the windows, casting rainbow shadows everywhere and glinting off the gold. Merlin felt like his brain was on overload.

As they took their seats in a pew Merlin looked around and asked how the church would fit everyone. Gaius explained on the way that this was where everyone who lived in the castle took their daily bread and that, similarly, there would be processions through the lower town to their local church as well.

Merlin noticed Arthur sitting about five or six rows ahead of him. Arthur turned around and appeared to be looking for someone. His eyes caught Merlin's and he smiled and nodded. Merlin nodded back.

The small babble of conversation ground to a halt as a low chanting started from the back of the church, by the doors. A procession of young boys started singing in Latin as they walked up the aisle. The boy in the lead was holding a pole with a cross on the top. The cross had the image of a man crucified. Jesus, Merlin's brain supplied. Behind them came the deacon and priest, which Gaius hurriedly whispered to him. The deacon was holding an ornate book aloft. The priest was holding a keg-like contraption, which was emitting a foul smell that made Merlin's head hurt and made him feel light headed.

"Incense," Gaius whispered. "Don't breathe too deeply if it makes you feel sick." Merlin nodded weakly.

The boys filed into more wooden pews on one side of what Gaius called the altar. The priest and deacon went and sat in high backed wooden chairs on the altar.

The priest stood. The singing stopped. The priest raised his hand. He moved it in a crossing fashion while saying, "In the name of the Father, and of the Son, and of the Holy Spirit."

There came a resounding, "Amen," from around Merlin.

He swallowed. No backing out now.

"So the bread and wine became actual flesh and blood?" Merlin asked, amazed. He had brought Prince Arthur his lunch and was now seated at his table asking him questions. Mass had ended an hour earlier and Arthur had called for his lunch. As he had walked in, Arthur had told him to sit down and tell him about his first experience with Christianity.

Merlin had confessed that he was confused as well as amazed. It seemed as if everyone had understood what was being said, even though it was all in Latin. Merlin supposed they all would have been attending Mass since they were very small.

Arthur had laughed and said, "We're still taught Latin. It's not entirely unused."

Now Arthur took a moment before answering. "Yes," he said slowly. "It's difficult to explain. From my understanding, it just happens by God's grace. Transubstantiation is what it's called."

"If it just happens," Merlin started, "how do you know that it's real?"

Arthur looked shocked for a moment. "We don't," he said simply. "We just have to have faith."

"How do I have faith?" Merlin asked.

It took Merlin a while to get used to the idea that there was something out there other than the Old Religion. Something substantial that he could hold onto. Arthur jokingly called him a doubter whenever Merlin was finding it difficult to have faith. But Merlin supposed that if Arthur could do it then so could he.

...

Months later, as Merlin watched over Arthur as he was dying from the Questing Beast's bite, the sorcerer bowed his head and said his first prayer.

*I didn't include the explanation or most of the Mass because I didn't want to run the risk of offending anyone. I figured it would be safer this way. Please tell me what you thought of this.