I have heard this before but a good reminder:
The pastor is to select some—and only some—of the men in his care to receive special attention and training because these are the men to whom he will entrust the gospel and the future of the Christian faith. But how will a pastor know what kind of man to choose? There’s an acronym I have found helpful. You may well have run into it before; I came across it most recently in a sermon from Steven Cole. The pastor must focus his attention on those men who are FAT:
What does FAT stand for? Faithful. Available. Teachable.
Much more here.