The Belgian admits the Reds faithful are able to lift the players while their fervent support negatively affects any outsiders who happen to visit Merseyside.
"The connection with the fans makes it much easier to step onto Anfield especially, and affects not only us players, but also the opponents," he told the Daily Mirror.
"Look at Villarreal, they were very impressed and maybe surprised by what was happening.
"That spirit has surprised teams now, and that is the mentality the manager has introduced.
"It happened against (Borussia) Dortmund too, they were affected by it. They are a team who have been through a lot, seen most things, have lots of experience, but that night showed what that atmosphere can do to players, can do to teams when they come to Anfield."