This series is intended for use by church leaders, ministers, informed lay persons, and bible teachers to obtain basic understanding of some of the concerns and issues found in a particular psalm, and then to use the psalm for present-day worship in song.

For each psalm there is a translation, treatment of its structure and theology, and then two to four musical settings: a "traditional" hymn setting and a "contemporary" setting, and sometimes also a verbatim chant. This variety demonstrates several ways of bringing the Psalms into Christian worship. With two or three exceptions, all of these metrical psalms are new compositions for Timeless. Most of the music in Timeless is intended for the average congregation to sing.

Timeless is an ecumenical and international project. While having its origin in the a cappella tradition of Churches of Christ, the book is based on the conviction that all Christian communions share the original hymnbook of the second temple and the church. The editor, therefore, has solicited commentaries, compositions, and lyrics from Methodists, Presbyterians, Baptists, Pentecostals, Roman Catholics, and others.