After they discovered the secret of the temple in Broken Sanctuary, the heroes weren't that pleased since they believed in Alister's words. The altar and so-called offerings were likely just a scam devised by some minor and intermediate gods.
Because of that, the heroes were hesitating whether to test it out or not.
In response, Alister shrugged, "We already came this far, so why not try it? If push comes to shove, I still have my goddess backing me in the god realm. Those minor and intermediate gods would dare not offend her."
"So let's try it out. For our offerings, it can just be a grand-level artifact."
The fact that Alister treated grand-level artifacts as nothing just showed how capable and rich he was. After all, grand-level artifacts could only be forged by Grand Blacksmiths and most of them were dwarves.