Believe it or not, Jim Cramer is an optimist by nature. If there is one key attribute he thinks successful investors will need when the Fed tightens, it is being an optimist. Maintaining a positive and skeptical stance will make everyone better investors.

"You need to have faith that things can be good for a long time or even get better than they are now. In other words, you have to bet on progress and on discouraging or middling days like this one," the "Mad Money" host said.

And while some may think this type of attitude is obnoxious, Cramer does not. The Fed is getting ready to raise rates, and each rate hike coming will test an investor's ability to stay in stocks. Each hike will make stocks more risky to own, and a positive bias will allow investors to find the stocks that can still do well in a more difficult environment.

So, what situations could make it worthwhile to own stocks during a series of rate hikes? Cramer listed four things that need to happen.

First, the U.S. could use some help from overseas. If Europe were to start growing, then European Central Bankers wouldn't be so determined to debase the euro at the expense of the dollar. And if China were able to pick up steam, then the U.S. could sell more exports to it.

Second, we need help from the government. More specifically, Cramer wants Washington to stay the heck away from business. If it wants to help, then the government should spend more money on infrastructure and roads.

"If our leaders can simply do nothing without shutting down the government in the process, then that would be ideal for the stock market," Cramer said. (Tweet This)

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Third, credit must get easier. The market can handle a slow and steady increase in rates. But if rates go higher and credit stays as tight as it is now, that could be a problem. It could mean fewer projects or even cancellations. But if credit is easier to get, then it could balance out when it comes to housing and small business.

Fourth, and perhaps the most key, is to find companies that can raise prices in a higher interest rate environment. When rates go up, investors will not be willing to pay as much for a company's future earnings. The price-to-earnings multiples must shrink.

A few examples of companies that could do well once the Fed tightens are companies without much competition, such as Constellation Brands and his favorite acronym, FANG: Facebook, Amazon, Netflix and Google.

So, while it will be harder to find winners once the Fed tightens, Cramer knows that an optimistic eye will be able to spot them.

"Take it from me, the pessimists will win a few portfolio battles, but the optimists will ultimately win the war," Cramer said. (Tweet This)

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