From 1971 to 1989 he was a lecturer for New Testament and Ancient Greek at the Theological Seminary in Reutlingen and was appointed its director in 1977.

From 1989 to 2005 Walter Klaiber was a member of the Presidium of the Association of Free Protestant Churches and its president for nine years.

From 1989 to 2007 he was a member of the board of Association of Christian Churches in Germany and was its chairman between 2001 and March 2007.

It is the standard work of the practical ecumenical Bible interpretation for life as a Christian today (1st edition 1994).

In 2012 he was awarded the ecumenical sermon price of the publishing house for the German economy for his life's work.