Many churches linked with Affinity would consider "Bible-centred Christianity" to be reformed, calvinist, and non-charismatic, although some in the affiliation would disagree. Thus, many member churches are defined by a rigorous theology, adopting a separatistic outlook. They regard churches with differing viewpoints as being in error and refuse to associate with them. For this reason they rarely join the Evangelical Alliance, a similar but larger organisation with a broader membership.
Groups of churches linked to Affinity include the Apostolic Church, the Association of Grace Baptist Churches, the Evangelical Movement of Wales, the Fellowship of Independent Evangelical Churches, the Free Church of Scotland, the Free Church of Scotland (Continuing) and the Evangelical Presbyterian Church in England and Wales and Ireland. At least two congregations of the Evangelical Connexion of the Free Church of England are also members.