Archuleta announced in December that he was planning to put his music career on hold while he carries out his religious duties.
He has now posted a video on YouTube, titled 'It's Not Goodbye', to bid farewell to his fans.
"It's been a very emotional week," Archuleta admitted, adding that he has been spending time with his friends and family before he leaves.
He continued: "I've been trying my best to get ready and prepare. I've been packing up. There's a lot of stuff you need - I mean, you're moving away for two years, so it's quite the task, I guess! But I've had a lot of help and I've really appreciated all the help from all those people who've been there helping and guiding and giving me tips and advice and just helping me get ready for this next phase."
Archuleta revealed that he will miss being able to keep in touch with his family, friends and fans and thanked his devotees for their support, repeatedly asking them to "respect" his decision to go on the Mission.
"I'm doing this to be able to have more one on one time with my Holy Father, with God," he said. "And I hope that you guys will respect that it's time for me to work on my relationship with Him and time with Him. I need to give Him the time that I've been wanting to and I've never given myself the time to do so. I hope you guys will respect that."
Archuleta concluded the video by saying: "I will see you all in two years. God bless - take care."
Last June, Archuleta revealed that God has been "guiding" him in his life.