The motto of the Worldwide Church of God is "Living and Sharing the Gospel." The following articles give more about evangelism:

As followers of Jesus Christ, we proclaim the gospel—we announce the good news of what Christ has done for all humanity. But the gospel is not just words to pronounce—it also involves practical application in our lives. When we accept the gospel of grace, it affects the way we think and the way we live. See Living the gospel, by Joseph Tkach.

Our place in prophecy is not to calculate dates, but to preach the gospel. We do not need to worry about the next phase of God’s plan—we need to be diligent about the phase of history we are currently in. This is the church age, the gospel-preaching age, and we need to be doing the work he has assigned us.  Evangelism is central to our mission, as described in Jesus’ “Great Commission.” See Sharing the gospel, by Joseph Tkach.

Sharing your faith: a series

1. Sharing your faith
2. Sharing with the unchurched
3. Sharing through friendship
4. Sharing with a New Ager
5. Sharing with another Christian
6. Sharing with a Muslim

Manual of Early Evangelism: a series of Bible studies by Lorenzo Arroyo
Part A. Jesus’ good news encounters with everyday people - 6 studies
Part B. The disciples' encounters with everyday people - 7 studies