ALPHARETTA, Ga. (BP)--Volunteering in short-term missions is one of the most effective ways believers can mobilize with far-reaching results. It also can be a life-changing experience, altering the way you view the world -- and your purpose in it. Volunteers with a heart for the spiritual needs across North America can turn to the North American Mission Board to find opportunities for making a difference. Right now is a great time to plan your next -- or first -- trip to the mission field; missionaries and pastors are ready to welcome short-term volunteers in the task of reaching the three out of four people in North America who don't know Christ. When is the need the greatest? All the time. Where is the need the greatest? Everywhere on the continent. Missions is living out your faith, and stepping out of your comfort zone, to mobilize in obedience to what God has called you to do to help meet the needs of others, with the result of introducing them to Jesus. Being on mission is doing this in a deliberate, intentional way. Could a mission trip be in your future? Fair warning: They aren't for the faint of heart. Living conditions can be uncomfortable -- consider the volunteers who helped after Hurricane Katrina. Even Vacation Bible School can be unpredictable, requiring flexibility and an attitude of servanthood.