He said during his appearance on "The View" Friday that the state needs to progress "soberly," with "eyes wide open" as it reopens.
"As evidence presents itself, we need to be able to pull those brakes and pull back," he added.
"My biggest fear is amnesia. My biggest fear is that we forget the reality of the last eight weeks, nine, 10 weeks in the state and in this nation and imperil, put ourselves at real risk of not just a second wave but recognizing that we're not even out of the first wave of this pandemic," Newsom continued.
On Monday, California released a framework that will permit counties to allow in-person worship services. They include limiting worshipers to 100 or less, taking everyone's temperature, limiting singing and group recitations and not sharing prayer books or other items.
"We hope people do this in a very thoughtful and methodical way," Newsom said Friday of reopening houses of worship in the state. "All of this is imperfect; perfect's not on the menu."
"We're trying our best to accommodate people's faith, their needs, businesses' needs to reopen, people's need and desire to get back out, but to do so safely," Newsom added. "I'm still humbled by all of this because it is a daunting challenge for governors all across the political spectrum, all across this country."
Despite the horrific impact the coronavirus outbreak has has around the world, Newsom said he takes solace in the fact that now the public has a "deeper understanding of [the] novel virus" and has in many ways become "deeply humbled" by the unknown that's been revealed.
"That's a frame of reference all of us have to bring into this next phase as we start to reopen our economy, to recognize that we are walking and venturing into the unknown, the untested," Newsom continued. "We have to be open to argument, interested in evidence."
"We can't be ideological about how we conduct ourselves. But fundamentally as a nation, certainly as [the] state [of] California, we're more prepared than we were certainly eight weeks ago," Newsom added. "[We're] more capable and more confident in our capacity to get through this and recover and thrive once again."
On May 8, Newsom signed an executive order to send mail-in ballots to every voter in the state for the November 2020 election. At the time, he said it was intended to protect registered voters from the virus by giving them the option of voting by mail if they considered it too risky to brave potentially crowded polling stations to cast their ballot in the Nov. 3 general election.
The Republican National Committee, National Republican Congressional Committee and California Republican Party filed a lawsuit against the governor and California Secretary of State Alex Padilla on Monday accusing them of using the coronavirus pandemic as "a ploy" to "rewrite the entire election code for the November 2020 election."
As flu season and the potential for a second wave to emerge in the fall, Newsom said he wants to provide Californians the opportunity to vote by mail, particularly when it comes to those most vulnerable to the novel virus, such as senior communities.
"We want to encourage them in a safe manner," Newsom said. "We think that's just foundational and fundamental to any good democracy."
Every episode of ABC's award-winning talk show "The View" is now available as a podcast! Listen and subscribe for free on Apple Podcasts, Google Podcasts, TuneIn, Spotify, Stitcher or the ABC News app.