Dr. Tiews specializes in the law of trusts, estate planning and estate and gift taxation, probate proceedings, will and trust contests, guardianships, adoptions, ecclesiastical law, the formation of foundations and nonprofit organizations, Medicaid and elder law counselling, and noncommercial real estate transactions. He has taught courses in philosophy of law at Aquinas College and Calvin University in Grand Rapids and has participated as a co-lecturer in National Business Institute, Inc. seminars dealing with Michigan probate law.

Dr. Tiews serves as attorney for the Presbytery of Lake Michigan of the Presbyterian Church (USA) and has served on the boards of a number of non-profit organizations.