The Hymn Renewal Project firmly supports the right of authors to receive all royalties due to them under law.  For this reason, HRP limits itself to renewal of works already in the public domain (beyond copyright protection).

HRP asserts a copyright in all lyric renewal that is substantial in nature.  HRP waives any claim to royalties for lyrics used solely in a congregational setting and not published widely.  Publishers should apply for permission to use the renewal lyrics set out herein.  ALL use of the renewed lyrics set out herein should be indicated by the statement "Lyric Updates by Hymn Renewal Project.  (c) 201__.   Used by permission."

With respect to works not in the public domain, HRP notes that some have opined that simple alteration of pronouns (and corresponding verbal agreement) is not sufficiently substantial a change to constitute infringement.  Although this is most commonly seen in singers changing "He" for "She" or vice versa, a shift from "Thou" to "You" would seem similar -- but no legal opinion or advice is expressed herein on that point.  Substantive lyric changes create a derivative work and the author has the right of control over these.  Should you wish to update lyrics in a song that still has copyright protection, application to the copyright holder will likely be necessary.  Consult an attorney for further advice.