In a thinly-veiled riposte to those campaigning for the UK to leave the EU on 23 June, the German MEP said this requires "European-level solutions".
Schulz was speaking at the two-day European Business Summit on Thursday.
The Socialist member called on the business community to "play its part" in making the case for the EU and its future.
But he admitted the EU was facing an "imposed crisis agenda" which "tests the capacity of European leaders."
The deputy argued forcefully that Europe must be strengthened and that issues such as the financial crisis, climate change or the refugee issue are better tackled at a European level.
Schulz said that EU heads of state and government should also have the "courage to explain to their citizens why we need the EU today more than ever."
He said that the EU is "not about giving up sovereignty, but about taking back control and governance in a globalised world."
His comments follow other remarks in made in Rome recently when, in a reference to the Brexit campaign in the UK, he said, "People who claim that nation states would do better to go it alone have lost touch with reality. Surely nobody really believes that, if our continent were to fragment, we Europeans, and our unique social model, could survive in an ever more globalised and interconnected world."
Also speaking at the summit, which ended on Thursday, Eurogroup President Jeroen Dijsselbloem said that Europe "needs to think about next decade, not just the next quarter."
"Europe's economic growth will be buoyed by increasing stability in the Eurozone. As progress is made towards putting Greece on the path to recovery and other countries show increasing determination to implement structural reforms, Europe appears to be moving in the right direction," he said.
But the Dutch official admitted that the Eurozone needs to be reformed and strengthened in order to make it more resilient in the face of future shocks.
"High unemployment and anaemic growth have dampened enthusiasm for the European project and Europe must deliver economic growth and financial stability," he said.
Meanwhile, Jeremy Corbyn, leader of the UK Labour Party, said that "too much" of the Brexit campaign has been dominated by "myth-making and prophecies of doom."
Speaking on Thursday, Corbyn, whose enthusiasm for the EU has previously been questioned, said, "In the final stage of this referendum, as we get closer to what is expected by many to be a very tight vote, it does not help the debate over such a serious issue if the hype and histrionic claims continue or worse intensify. I believe the EU has the potential to deliver positive change for the people of Britain if there was a radical, reforming government to drive that agenda.
"Too often what has held back the EU is having to move at the pace of the slowest. Too often that has been the British government."
Two weeks ago, Boris Johnson claimed: "It is absurd that we are told that you cannot sell bananas in bunches of more than two or three bananas."
Corbyn said, "What's absurd is for a senior politician, a former Mayor of London, to say, 'Vote to Leave the EU, they're after our bananas!'
"The Leave side has concocted a number of myths about the evils of the EU. Many are, frankly, bananas."
He added, "So let's remind ourselves of the positives it was EU regulation that improved the UK's beaches which, if you go back 30 or 40 years, were in a terrible state .
"Britain used to pump our untreated sewage straight into the sea. Just 25 years ago one in four British beaches were too dirty to swim in. Now 95 per cent of our beaches have a clean bill of health.
"Three years ago the EU voted to restrict the use of some pesticides that are strongly linked to the decline of the bee population, essential for our biodiversity. The coalition government lobbied against the restrictions but they passed."
In the speech in London, he concluded, "Britain will be stronger if we co-operate with our neighbours in facing those challenges together.
"Europe needs to change. Today, I've outlined some areas for progressive reform. But those changes can only be achieved by working with our allies. There is an overwhelming case to remain and reform so that we build on the best that Europe has achieved."