Five is the number of trophies won in 2015 by Barca, who are Champions League and La Primera holders.
Suarez is adamant standards must remain high:
"Always, after a competition like this, teams can have a dip," Suarez told Spanish television.
"Our next challenge now is not to drop off, to keep challenging for trophies. We must stay on the same path, we are the best team in the world."
Messi was a doubt for the final along with fellow attacker Neymar, who returned from an adductor strain.
"They wanted to play this no matter what," Suarez said.
"But this is not just about Leo and Ney, but the whole group who played so well."
River qualified for the Club World Cup following Copa Libertadores glory.
Barcelona still have one more match remaining before the start of 2016 - a home game on Wednesday week against Real Betis.