newadvent.org
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New Advent is an online Catholic reference library. It offers the Catholic Encyclopedia, writings of the Church Fathers, the Catechism, saints and feast information, and other Catholic theological and liturgical resources.
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BibleProject
The creators of BibleProject have in-depth conversations about the Bible and theology. A companion podcast to BibleProject videos found at bibleproject.com
thegospelcoalition.org
An online hub for Reformed evangelical theology, The Gospel Coalition offers articles, essays, sermons, podcasts, and Bible study resources on theology, ministry, and culture.
Desiring God
Sermons, articles, and books from John Piper's ministry, covering Reformed theology, biblical exposition, and Christian living. Readers get a large searchable archive plus the doctrine of Christian hedonism that shapes Piper's preaching.
Blue Letter Bible
Free study site pairing the biblical text in multiple translations with Strong's numbers, Greek and Hebrew lexicons, interlinears, concordances and public-domain commentaries. Clicking any word opens its original-language entry, so you can check a translation choice yourself.
Introduction to the New Testament History and Literature
Explore the historical and literary landscape of the New Testament with Yale Professor Dale B. Martin. Understand early Christianity's foundations.
OnScript
Bringing you engaging conversations on Bible and theology (hosted by biblical scholars and theologians).