Speaking to Yahoo! Singapore about his decision, the exuberant singer-songwriter who is in town to promote the reality TV singing competition and his music said, "It was a really hard decision and it took me a couple of years to make the decision."
"I actually considered doing it during pre-Idol days but it wasn't on my mind as much until after Idol. Besides, I was still under contractual obligations with my label then," he revealed.
The former runner-up from the seventh American Idol season insisted that it wasn't a hasty decision. "There were a lot going through my head when I was making the decision. I am giving up what I worked so hard for, leaving my family and fans behind," he said.
"But I know it's worth it. It is a calling from within and it's exactly the same feeling when I went ahead to quit my job to audition for American Idol," he added.
The baby face Idol finalist, who turned 21 two months ago, feels very fortunate to garner support and encouraging words from his family and fans. "My family was very surprised and made sure I thought about this thoroughly. My mum taught me to follow my heart and I did," he grinned.
"My fans are mixed about it though. They don't want me to go but it's cool to see how supportive they have been and the respect they have shown towards my decision," he said earnestly.
Knowing that this is what he wants and willing to put everything down, David feels happy that he is setting a good example. "A lot of people in my church were undecided to go on a mission. But after seeing what I did, they told me they have decided to go too. It's so cool to hear that," he laughed.
But Archuleta will not be leaving his fans in a lurch. The singer has it all planned out. "Even though I cannot perform while I am gone, I am still going to record music before I leave," he said.
"I am not going to leave my fans empty handed. I am not sure what the rules are going to be like but I will update my fans with a quick email or video whenever time permits," he added.
Watch the video of Archuleta's latest song here.
Catch the live simulcast of American Idol 11 on Star World, Ch 501, 6.30pm every Thursday and Friday.