David Helm has written a great book called One-to-One in which he makes the case for a very simple but effective strategy in ministry: Bible Reading.
One blurb puts it this way:
Can you think of people in your life that you would like to see progress spiritually–perhaps
a non-Christian colleague, or a Christian friend at church, or a family member? Here’s a way to help them understand more of God in a way that is simple and personal, and that
doesn’t rely on getting them to a church program or event. All this is possible through one-to-one Bible reading.
And if that wasn’t simple enough, Bradley Aucoin has written a two-page summary of Helm’s book which you can find here: Reading the Bible One On One.
You will be profoundly encouraged at the simplicity of the ideas and, if you should try it, the results of this simple approach to ministry.