Penny works several evenings on a puzzle, fitting each piece carefully. With two young sons helping her, however, she often finds an elaborate puzzle completed except for one or two missing pieces.

Its amazing how those missing pieces stand out. It doesnt matter how small or insignificant the pieces are. When theyre missing, theyre more noticeable than the brightest, largest pieces in the puzzle.

It seems to me that Gods plan for spreading the gospel is like a puzzle. Each Christian is assigned a small piece of the plan. The Christians who make up the framework are pastors, full-time career missionaries, long-term volunteers and some ordinary on mission Christians. They help to create the infrastructure in which the rest of us find our places of service.

Some pieces of His plan seem bigger and more prominent than others.

Every piece is important to completing the work. And no piece seems more prominent than when its missing. Spiritual giants are wonderful, but rare.

The world is filled with everyday Christians. And just as millions of tiny raindrops band together to form a great river down which a ship can navigate, great numbers of individual Christians each filling a crucial part of the puzzlecan accomplish the Great Commission.

The spiritual needs of our nation and the world are so enormous that it will take everyoneon mission Christians, short-term and long-term volunteers, career missionariesto meet them.

God calls all of us to His service, and His plan includes enough workers to get the job done.

Some of us dont respond or we dont listen carefully to the exact callthe piece of the puzzle He created just for us. And 1.8 billion people have little or no access to the gospel.

he first step is hearing and understanding the call. When the child Samuel was in the temple, he heard someone call his name. Three times he went to his mentor, Eli, and asked if hed called. The third time he approached Eli, this wise leader realized God was calling Samuel and gave him counsel thats relevant today. He told Samuel that, next time he heard Gods voice, he should say, "Speak, Lord. Im listening."

When Samuel recognized God speaking to him and listened, God clearly laid out His plan. When we say, "Speak, Lord. Im listening," God will lay out His plan for us.

Our call can lead us into one of several pools of mission workers. To reach todays world for Christ, we must enlarge all these pools.

• The on mission Christian, the believer who gets off the bleachers and into the game, who heeds the call that comes to every Christian.

• The short-term mission volunteer whose lifestyle is morphed a bitstretched, adjusted, enlargedbut basically remains the same.

• The career missionary or long-term volunteer whose way of life is totally changed.

I believe God uses the same methods for all these calls and even uses the first two experiences to call Christians to the third.

The main thing is to listen to the call and see where it takes us.

We can do our part in helping othersand ourselveshear and respond to Gods call by creating an environment where Gods call is clear. Following are some environments where He often calls.

Mission education is a time-honored way of preparing us for a call to mission service. God used mission education to whet the appetites of new and maturing Christians for lifestyle, short-term and career mission service. Over and over, the book of Acts tells of missionaries like Philip (Acts 8: 5-14), Paul and Barnabas (Acts 14:27), and Peter (Acts 11:1-18), who returned to their home churches and reported on their missionary journeys.

Such communication was a precursor to todays methods of learning about missionaries through magazines, videos and other modern means. And, 2000 years later, theres still no experience quite so inspiring as hearing a real, live missionary.

Today, mission education can help children, youth and adults recognize mission needs, how theyre being met, how they can support the work of missionaries, and how they can be personally involved. And they can equip students of all ages with understanding and skills for the mission.

Every church with a heart for being a worldwide mission-sending agency can provide mission education and hands-on mission opportunities.

Mission education organizations, mission education strategies, On Mission Celebrations and other mission opportunities and events are crucial to an on mission church. Theres a twofold benefit. The church becomes a mission lighthouse in its community. And it becomes the launching pad for missionaries, expanding the churchs influence worldwide.

Ive had the privilege of hearing newly commissioned missionaries speak on several occasions. A common thread of their words is gratitude to their home churches for supporting them, giving them opportunities to serve, and providing mission education organizationsRoyal Ambassadors and Girls in Actionto open their eyes to missions. Through mission education, they learned to recognize a missionary when they saw one. And they were able to understand and focus on the call when they sensed it.

The early church set the standard for personalized missions. They sent out missionaries. They participated in local mission projects, but also reached out to their Samaria (literally, Acts 8:1-5) and collected a world hunger offering (Acts 11:27-30).

Churches that have followed this tradition have seen missionaries emerge from their efforts. Most missionaries will tell you that they were short-term mission volunteers before they became career missionaries. Most had been involved in local mission projects, gone on church-sponsored mission trips and participated in denominational mission endeavors such as World Changers. Many had heard missionaries speak at On Mission Celebrations (formerly World Mission Conferences).

Most people who go on short-term mission trips have fulfilling experiences. They return to their lives with a desire to "do it again some time."

Others are like the woman I met recently. She had just returned from a year in South America, using her secular skills to assist a missionary. Now she felt God calling her to career mission work.

"I dont know exactly what He wants me to do," she explained. "But one thing I know. My life is too changed to ever go back to what I was doing. Im ready to walk away from my plan for my life and join Gods plan."

The need for missionaries is greater today than ever, but its never been so easy to communicate the call. Its as close as our fingertips.com. Mission groups can log on the Net at their weekly meetings and chat with live missionaries. They can watch videos that bring missionaries to the smallest meeting in the remotest area.

More information about mission causes exists today than ever before, and the format is limited only by your imagination and your techie tendencies. Many resources are provided by the North American Mission Board and the International Mission Boardonline tools for helping Gods chosen recognize their call. Can God call us to His mission plan by video or website? He certainly can.

Sometimes God calls us through the needs we see around us. Lydia was a businesswoman, layperson and church starter. She saw a need and acted on it. There was no synagogue in Philippi, and no chance of building one without the required number of Jewish men. That didnt stop her from organizing a worship service right on the riverbank perfect for all the baptisms that resulted from her church start. And her lay efforts opened the door for full-time missionary Paul.

Christians can be called to service just by visiting an area or people group and seeing the needs. But few things are as frustrating as seeing a need and not having the knowledge or necessary process to respond. People who sense a need and feel led to meet it need guidance and structure from on mission individuals and churches.

Missionaries dont all preach or plant churches. International missionaries include accountants, farmers, doctors, dentists and business managers. These missionaries use their skills to meet needs, gain trust and open doors for sharing the gospel.

When we realize that God can use our vocational skills, our talents, even our hobbies in His service, were more likely to sense Gods unique call on our lives.

Campers on Mission is an example. People of all ages have discovered that God can use their love of camping to share Christ with other campers. Each year, 3,500 campers mix recreation with spreading the gospel. Last year, more than 1,500 people came to know Christ as a direct result of the Campers on Mission ministry.

Tomorrows mission force is in your church today, and youre part of it. The question isnt whether God is calling you out. The question is to what extent. Whether Hes leading you to become an on mission Christian. Or to make a few comfort changes. Or to make reaching people for Christ your career. Whatever Hes leading you to do, will you join Him in His plan? A major factor in responding is your reason for doing so. Henry learned this years ago from frog pajamas.

Henrys 8-year-old son first saw the fabric and to him it was wonderful, just right for his dad.

"Mom, can we buy this and make something for Dad?" Thinking quickly and creatively, Henrys wife said, "It would be perfect for pajamas."

So thats how Henry got pajamas with frogs of all colors on them. He wore them cautiously, making sure his son knew he appreciated them and that no one else knew he owned them.

Until a cold night in November. Henry and his wife were reading in bed, waiting for their teenaged daughter to come home from a date. Suddenly, they heard a noise outside their window. They looked out to see their daughter and her date being harassed by the six-foot quarterback from their high school.

As the voices grew louder, Henry told his wife, "Im going out there." Immediately, she saw him race from the room, the colors on his frog pajamas a blur as he ran.

Henrys wife watched as he shook his fist in the face of the boy who was six inches taller and 75 pounds heavier. The surprised young man got in his car and sped away.

As a triumphant Henry entered the house, his wife could hardly wait to ask, "How did you have the nervefrog pajamas and allto stand up to that big guy?" Henrys immediate reply: "Love makes us bold!" Does your love for Jesus Christ make you bold enough to say, like Samuel, "Speak, Lord. Im listening. Im ready to join Your plan for my life, regardless of what that means"?

Mary Branson is marketing director of the North American Mission Board.