Leah has served as a full-time missionary with Cru for 46 years. Cru is an international, interdenominational Christian movement committed to helping fulfill the Great Commission in this generation. Leah serves as a faculty member of the seminary run by Cru, called the International Graduate School of Leadership (IGSL) (https://igsl.asia/) located in Manila, Philippines. Her responsibility is to provide faculty and alumni care, especially for the women. The seminary trains pastors and missionaries coming from 30 countries located in Asia which consists mainly of Hindu, Muslim, Buddhist, and Communist people groups.

 In addition to her responsibilities with the faculty and alumni, as a faculty member of the seminary, Leah is expected to do what is known as field ministry. Her ministry is leading Bible Studies. She started the first Community Bible Study International Class in the Philippines in 2005 and now has many groups reaching thousands of people through her you-tube classes. These Bible Studies which Leah leads throughout the year aim to make disciples of Jesus Christ through caring, in-depth Bible studies available to all. and others. She trains others to initiate and lead Bible studies all over Asia as well.