Don’t—not unless you have taken a long and hard look at what starting really means, are willing to be tested on the things that make you and break you, and can endure the blows of rising and falling—and then get back up—over and over again.

There’s the idea of having a startup, and there’s the reality of actually starting it. The truth is that it’s a balancing act, a roller coaster ride, and a lot of sleepless nights.

But in order to make it, entrepreneurs cannot just pick an idea out of the blue. Consider the following criteria before you come up with an idea for your startup:

1. Old and proven

If you think you have an idea, know that it may not be original, and that someone else has most likely thought about it before. That said, old concepts that are outdated, but have proven to work, typically offer great startup ideas.

Consider Uber, which is valued at $62 billion. What’s fueling its growth engine and making Google (GOOG) Ventures invest $258 million? The fact that it disrupted a calcified industry (a.k.a. taxi service) with new technology. Gone are the days of flailing your hand in the air for a cab. You can now push a button, prompting a car to pick you up in 8 minutes. There’s never a truly new idea, but there are disruptive ideas. So why not take an old one that has proven successful and make it innovative?

See also: Here’s How to Avoid a Disastrous Startup Idea

2. Belief and conviction

Make sure your idea is one that you believe in and have a sense of conviction about. Belief is based on your experiences, perceptions, and background. Conviction takes that belief and pushes it through with intelligence, courage, labor, determination, and expectation. The synonymous correlation between the two is what creates buy-in.

You need to authentically and wholeheartedly buy-in to your own idea, so that you create the same sense of buy-in when you pitch it to your investors. A startup based on belief and conviction will also help you get through the hard days. At Vanderbloemen Search Group, we found a solution to the challenge of team-building that hundreds of faith-based organizations face across the world. What gets us through challenges as a company is our belief and conviction that we get to help faith-based organizations through a sacred process, as pastoral roles involve calling as much as background and skillset. Make your startup stand up and out by finding, rooting, and solidifying your idea in your beliefs and convictions.

3. Strategy and significance

Follow the advice I give my kids for picking a job: Find something that you’re good at, is needed in the world, you enjoy doing, and leaves the world better than you found it.

This motivates them to not only consider an idea for their job, but also to find value, purpose, and intent in it. These four points go hand-in-hand. You can’t initiate a startup you’re skilled in and enjoy doing if it serves a purpose that is void of significance.

Similarly, if you have an idea that makes you the next “world changer,” but you don’t have the chops to execute it, you’re setting yourself up for failure. The startup entrepreneur that grew up in a poor Brooklyn housing project was none other than Starbucks (SBUX) CEO Howard Schultz, who simply wanted to create a “third place” between home and work that offered the peace and pleasure of community. He created his company strategy centered on this significant concept—community. And he had proven success to bring it to life.

Don’t just pick an idea and start a company. Think through these guidelines first, and remember that starting a company is not for the faint of heart. You will invest intangible unmeasurables in it—ownership, showing up, risk-taking, transparency, humor, faithfulness, integrity, and leadership.

Startups are tough work, and they require careful choosing, heartfelt passion, and a lot of guts.