Ivan explained in a DM to Bachelor alum Caila Quinn that Tayshia "only wants to date a Christian and I'm not religious."
He went further into detail on Kaitlyn Bristowe's Off the Vine podcast, revealing that Adams asked if he'd raise his children to be religious.
"I kind of explained to Tayshia, 'Listen, I'm agnostic,' and being agnostic is, a lot of people confuse it for being atheist, which is not what I am," Hall said. "Atheist is taking a hard stance that there is no God, and that's not what I believe at all. It's completely different things, but everybody confuses it. Agnostic is strictly saying, 'I don't know.'"
Ivan said Tayshia then asked him detailed questions about his beliefs -- "is there a heaven or is there a hell, that kind of stuff," he recalled.
"My answer's gonna be different than yours," he said he told Tayshia, "because I'm going to tell our kids, 'I don't know what there is.' And then you can tell the kids whatever you want, and you can take them to church, that's completely fine with me."
"You can have whatever religion you want, my main focus are the morals and values that you have, and that's what I try to have," he added, noting he's dated women of all religious backgrounds. "I just try to have good morals and values, that's what's most important to me."
"For Tayshia, it's something different, where she, I guess, actually wanted to date someone who is Christian," he shared. "And that's completely fine, and that's how a lot of people are."
Tayshia, meanwhile, said in an interview with ET's Lauren Zima on Wednesday morning that religion was just one of the reasons she knew Ivan wasn't her future husband.
"I think the beauty of the fantasy suite date is that you have that opportunity to really talk about things you might be shy talking about in front of the camera... really diving into the nitty gritty of a relationship and what the future could possibly look like," she said. "Sure, religion was one of the reasons, but there were multiple things that we talked about that we kind of didn’t align on."
"And at the end of the day, when I was looking at my relationships with Zac and Ivan, it was just that I saw my future with Zachary, that was where my heart led me, and I can only just lead to that. Unfortunately, that was where it just had to end," Tayshia continued.
During his exit from the show, Ivan expressed doubt that Tayshia would end up with anyone on The Bachelorette (she ended up engaged to Zac Clark).
"I heard that," Tayshia told ET. "That was interesting to me."
The 30-year-old added that she never thought she would leave her season single, but did question whether she was really happy. "I feel like you have to be open to all possibilities. And I feel like if you were to stress yourself out and be like, I have to get engaged, are you really doing it for the right reasons? Are you going to be happy down the road?" she asked.
"I think it goes back to the fantasy suites. You have conversations, and at that point -- it’s weird for me to vocalize, this relationship is there, or this relationship is there," she shared.
During their breakup, Tayshia told Ivan that he'd been a steady source of support for her all season -- the two even shared that they were "falling" for each other during Monday's fantasy suites. However, the Bachelorette said, "This past week, we've talked about some important subjects... There are some things that kind of posed concern."
"I wish I could say that there were a lot of red flags prior to this week. And there haven't been," she continued. "It's just like, at the end of the day, religion's part of my morals and my beliefs."
While Tayshia didn't clarify what exactly she was referring to in terms of their religious differences, she did mention in Monday's episode that she and Ivan had talked about religion during their overnight in the fantasy suite. And for his part, Ivan seemed to understand what was happening.
"I definitely get it... That is the roadblock for the two of us," the aeronautical engineer admitted. "I was definitely struggling with bringing it up, 'cause, you know, all the girls I have dated in the past, it never ended because of religion or anything, but I know that's something that's important to you."
"I really do think the world of you," Tayshia assured, apologetically.
"It's all good. It just sucks," Ivan replied. "I meant every word when I said I was falling in love with you this week, and I just hate that it couldn't work out."