I just confuse and want to clarify, when i reset the firewall current state table, that is the only time that firewall rules will take effect?
No, after you change rules only new connections will match new rules. The keep state will keep current connections working until it ends or until you reset states.
you start a ping to 18.104.22.168, then create a rule to block ping.
The result will be a sucesfull ping.
if you reset states, then ping will fail.