He broke the news on his Facebook account, saying his initiative had been well-meant but rushed.
"I am stepping down from my nomination for president and withdraw my candidacy in the elections," he said.
He said his purpose had been to foster a united society in Latvia.
"I see that there are many acute problems in Latvia that need urgent solutions. I wanted to go fast and do what I can. But in order to get far, I need to go slow," he said.
Sproģis also noted that he had not become a member of the party, and that he has never been a member of any party.
Harmony, which traditionally relies upon solid support from Latvia's ethnic Russian minority, now identifies itself as a "social democratic" party, though on many issues it is far from the European social democratic mainstream.
Sproģis earlier came under fire on Twitter for his choice to side with a party seen by some as pro-Kremlin and pro-Russia, with Twitter users doubting Sproģis' newfound political consciousness.
As reported, he gave an interview to the Ieva magazine before being nominated by the party. The magazine then claimed that the preacher had mislead them.