This applies to evangelism. It is common for churches to have evangelism training seminars. People come. They listen. They take notes. They stay awake the entire time. Then they leave and go back to the normality of neglecting evangelism.
The key is to have an opportunity every week to talk about evangelism. That can take place in a small group or Sunday School class. But it must be part of the normal schedule. There must be an opportunity for reporting and planning on a weekly basis. For evangelism to take off, it is critical to have space in the schedule so people can report on their evangelistic activity that week. Then there needs to be a time to share plans for the coming week. Having a regular discussion time will help put feet to evangelism.
Of course, have the seminar. But don’t stop there. Follow through with a weekly checkup.