Finding a stock you can hold forever isn't easy. The business needs to be strong enough to handle any changes that may affect its operations or even its industry. This year has been a powerful reminder of just how vulnerable businesses can be, especially those dependent on in-person traffic, like airlines, restaurants, and retailers. Even notable companies are struggling amid the COVID-19 pandemic.  

But the companies listed below -- Becton, Dickinson (NYSE:BDX) and Visa (NYSE:V) -- are in safe industries, and their businesses are strong enough that they're likely to survive economic volatility, including pandemics and recessions. Here's why both stocks are safe buy-and-forget investments that you can hold in your portfolio for as long as you live.

1. Becton, Dickinson

Becton, Dickinson is a global supplier of medical instruments and supplies. And that global reach is one way the company offers investors long-term stability: It isn't dependent on one individual market. In the 2019 fiscal year, the company recorded revenue of $17.3 billion, up 8% from last year. Of that, $9.7 billion, or 56%, came from the U.S. market. The remainder came from international markets, with Europe making up the largest slice at $3.4 billion.

Hand holding an hourglass with dollar signs around it.

Image source: Getty Images.

It's also diverse in its product offerings. Just over half (52%) belong to its medical devices segment, which relates to the delivery of healthcare and includes items like syringes, needles, and catheters. Its life sciences products, which help collect, transport, and diagnose specimens, accounted for 25% of the company's revenue last year. And the interventional segment, which includes products that will only be used once (like grafts and other surgical items), makes up the remaining revenue mix.These items are essential for day-to-day operations at hospitals, and their importance to the healthcare industry means that demand for Becton, Dickinson's products isn't likely to go anywhere.

The company released its third-quarter results on Aug. 6 for the period ending June 30, and sales of $3.9 billion were down 11.4% year over year as the COVID-19 pandemic led to fewer elective procedures performed at hospitals. But as the number of operations slowly goes back to normal, Becton, Dickinson's revenue should also recover.

In the meantime, it's adapting to the current situation. The U.S. Food and Drug Administration (FDA) has so far given an Emergency Use Authorization (EUA) to three of the company's diagnostic tests for COVID-19. The latest approval came on July 6 for a rapid point-of-care SARS-CoV-2 test to be used with the company's BD Veritor Plus System. The test can provide results within 15 minutes. By the end of September, BD plans to produce 2 million of the new tests every week. Adaptability is crucial for any forever stock, as investors will want to know that the company is versatile and able to innovate quickly.

A forever stock should also give investors an incentive for holding it. Becton, Dickinson only pays investors a modest dividend of 1.2% -- far less than the 2% you'd expect from an average S&P 500 stock. However, the company's payouts are likely to grow over the years; it's a Dividend Aristocrat that has raised its payouts for more than 40 years in a row.

2. Visa

Visa is in another fairly stable industry: financial services. The credit card company provides an important service to the economy, facilitating payments in person, online, or over the phone. Its credit cards are used all over the world, and in its case as well, that global footprint makes the company a stronger investment. More than half (55%) of its net revenue generated in the most recent fiscal year came from outside the U.S.

The company's also still showing growth, with revenue up 11.5% in fiscal 2019 to $23 billion. In each of the past seven years, its operating margin has been above 60%, leaving plenty of room for the bottom line to stay in the black even if factors outside its control start to weigh the business down.

Third-quarter results, released July 28 for the period ending June 30, showed net revenue of $4.8 billion declining by 17% year over year. Nonetheless, the company posted a solid profit of $2.4 billion. Thanks to its strong financials and lots of margin to help cover expenses, Visa's in a good position no matter what happens in the economy.

The stock does offer investors a dividend, but its yield is a bit more modest at 0.6%. And although it's not an Aristocrat, Visa's increased its dividend for more than 10 years in a row.

You could decide to invest in Visa's rival Mastercard instead, but at a lower price-to-earnings multiple (40 versus 48), Visa is the cheaper buy today.

Which stock should you buy today?

Before deciding which of these stocks is the best buy, let's take a look at how both Visa and Becton, Dickinson are doing against the markets this year:

BDX Chart

BDX data by YCharts

Visa's only slightly underperformed the S&P 500 thus far, and Becton, Dickinson is well behind, with returns of just 2% year to date. But shares of Visa do look cheaper:

V PE Ratio Chart

V PE Ratio data by YCharts

Average P/E ratios differ by industry, with financial services at about 14 and healthcare near 19, but that's only part of the reason that even prior to the pandemic, shares of Becton, Dickinson had much higher earnings multiples than Visa's. With a simpler business and a lower valuation, Visa's a better buy overall -- although if you're an income investor, the healthcare stock may be a better fit for your portfolio.