You have a lot of things competing for your attention. You have messages to check, calls to return, articles to read, decisions to make, things to buy, and forms of entertainment to choose. This world overloads and overwhelms you with information.

Here is one simple tool to navigate this tempest and give you greater peace of mind: focus.

Did you know that you literally cannot devote your attention to two things at once? In his book Brain Rules, neuroscientist John Medina writes, “Multitasking, when it comes to paying attention, is a myth. The brain naturally focuses on concepts sequentially, one at a time. … To put it bluntly, research shows that we can’t multitask. We are biologically incapable of processing attention-rich inputs simultaneously.”

Medina explains how, when you focus your attention on something, the blood in your brain shifts to the anterior prefrontal cortex. This cortex works like a switchboard: It finds the right neurons to do the job and switches them on. This takes several tenths of a second.

When you switch your attention to a different input or stimuli, your brain has to disengage from the first one, find the neurons for the new input and switch them on. All these steps have to take place every time you switch tasks. “It is time-consuming. And it is sequential,” Medina writes. “That’s why we can’t multitask. That’s why people find themselves losing track of previous progress and needing to ‘start over,’ perhaps muttering things like ‘Now where was I?’ each time they switch tasks.”

Getting interrupted causes tasks to take longer and increases the errors in our work, studies show. How much is this problem affecting your work, every day?

The solution is focus. But how to do it? Here are three ways.

First, focus on a goal. You won’t accomplish something unless you put it at the top of your list. The Power of Less author Leo Babauta writes, “Focus is the most important factor in determining whether you’ll achieve a goal or stick to creating a new habit. Not self-discipline, not rewards, not sheer willpower, not even motivation (though this is also an important ingredient). If you can maintain your focus on a goal or habit, you will more often than not achieve that goal or create that habit. If you can’t maintain your focus, you won’t achieve the goal, unless it’s such an easy goal that it would have happened anyway.”

What are your priorities? God establishes our most important: “Seek ye first the kingdom of God and his righteousness …” (Matthew 6:33). Put God first each day in personal prayer and Bible study, and in working to live right.

Apply this same principle in your daily work: Do your most important task first. Don’t do anything else until this is done. And be sure that it is moving you forward on your larger, most critical priorities. Focus on your goal to dictate your daily priorities and tasks.

Second, focus on the task at hand. Keep your mind wholly engaged on what you are doing at the present moment. “Let your eyes look directly forward, and your gaze be straight before you” (Proverbs 4:25, English Standard Version). When distractions or even other priorities begin to enter your mind, push them out and return your full effort to the one thing you are doing right now.

Mr. Medina boils it down to this: “Do one thing at a time.” Forget multitasking: Instead, single-task! “Whatsoever thy hand findeth to do, do it with thy might” (Ecclesiastes 9:10).

Eliminate clutter in your workspace. Turn off your cell phone. Shut off e-mail and the entire Internet if possible. (You can accomplish this with a productivity app like the one I use, which is called, appropriately, “Focus.”) When you feel the urge to check your messages or jump to another task, stop yourself. Refocus. If another issue arises while you work, quickly make a note of it and return to the task at hand. Refocus.

When you’ve completed your task, process those notes and adjust your to-do list and schedule as necessary. Batch process e-mails or other messages; check your inboxes at regular, predetermined intervals rather than constantly having them open.

Third, focus on completion. Don’t get so wrapped up in your planning, prioritizing and scheduling that the preparation itself becomes a distraction. Your real focus must be on getting your priorities done. Each day, make sure you’re moving those forward toward completion.

“Anytime you find yourself procrastinating on an important task, see if you can break it into something smaller. Then just get started,” Babauta writes. “Don’t procrastinate, but just get started. Once you’ve gotten started, you will gain momentum, and will have broken through the initial resistance barrier, and you’ll be much more likely to continue to the next small task and the next one until the large task is completed. Small tasks are always better than large ones.”

Training yourself to focus is about more than just increasing your productivity, it’s about building your character. As the May 1985 Good News put it, “Proper management of time depends on proper management of yourself.”

Focus on your goal, focus on the task at hand, and focus on completion. And whatever your hand finds to do, do it with your might!