Israel Folau will front a code of conduct hearing in Sydney on Saturday after being charged by Rugby Australia's Integrity Unit last month for posting on Instagram that gay people and others he considered "sinners" were destined for "hell" if they did not "repent".
Mapusua said Folau has the right to express his religious faith but it should never to be the detriment of another human being.
"There's always been players of different ethnicities, beliefs, religions and the common thing has always been being able to come together and that was through rugby," he said.
"In terms of what Israel Folau's doing my view is that is a very isolated incident or situation. The way I see it is that is an employment issue between himself and Rugby Australia."
Growing up in a Christian family, Mapusua said his faith had always been about love and that's how he's tried to express his beliefs.
The former Highlanders and London Irish centre said there was some confusion among Pacific Islands players about what they can and can't post on social media.
"It's almost divided the Pacific Island rugby players community and it comes down to what those players' understanding is of the situation...I feel like there might be a few Pacific Island rugby players out there that maybe are a bit torn as to what's going on and maybe feel like they're unsure where they stand or the opposite, they're absolutely sure of where they stand," he said.
"The sooner they can sort it out, I think, and get some clarity around what exactly is happening I think the better it will be for everyone."
Seilala Mapusua said religion was "natural" and part of every day life when you're involved with a Pacific Island national team.
But he admits it's a lot different for players in the social media age.
"It kind of came in towards the second half of my career and we didn't have these issues. The players now are having to deal with a lot and the more understanding they can get around social media and what it comes with and support around it (the better because) they're having to deal with a whole different beast."
A founding board member of Pacific Rugby Players Association, Mapusua said his organisation conducted workshops with teams in Fiji, Samoa and Tonga to help prepare them for life in a professional rugby environment.
"We talked about when you sign a contract what that comes with and your role and your responsibilities. It's not just about you play rugby and get paid this amount of money, it's more than that, and so we try to educate our players before as opposed to trying to put fires out when they're already happening."