He doesn't have to work hard at it. The fruit comes later. And I do believe that Jesus does give us fruit. He does provide us with a victorious life. Salvation is as easy as eating pie.
Little children have a simple humble trust.
No complicated qualifications. This text does not say that to be saved you must take graduate studies from universities and become as academic theologians and scholars, delving deep into the great unfathomable difficulties of salvation and only those graduating summa cum laude will be saved. If we must become like children, then it can't be all that difficult or hard to be saved. The good news is that it is not hard. The gospel is the good news that Jesus visitation to this earth has already paid it all and salvation is ours for the taking.