We've sometimes put together posts that link to some representative material we've written over the years on a particular topic. What's below is a list of such posts. The list could be updated or expanded in the future. You may want to check back on it from time to time.
To find material on more specific topics within the posts, you can use the Ctrl F feature on your keyboard. (Press F while the Ctrl key is held down.) For example, the afterlife post linked below covers Heaven, Hell, Purgatory, universalism, and many other issues. To find material on a specific subject within that page, press Ctrl F and search for the relevant term. The title of each post will be followed (in parentheses) by a few examples of the subjects covered.
Before I get to those posts, however, I want to link some resources that are relevant to studying many of the topics addressed below. Steve Hays has written a bibliography for the Old and New Testaments, including recommended commentaries for individual books of the Bible. Here's something I wrote about how to study the church fathers (early Christian sources outside the Bible).
The Historical Roots Of The Reformation And Evangelicalism (church infallibility, apostolic succession, sola scriptura, etc.)
Christmas Apologetics (the virgin birth, Jesus' birthplace, Luke's census, etc.)
Easter Apologetics (the empty tomb, the hallucination theory, dwindling probabilities, etc.)
Early Christian Moral Standards And Practice (honesty, abortion, polygamy, etc.)
The Reliability Of The New Testament Text (pre-manuscript evidence for the text, the ending of Mark, whether we need inerrant copies of the originals, etc.)
Evidence For Modern Miracles (whether extraordinary claims require extraordinary evidence, cessationism, resources on modern paranormal research, etc.)
A Christian View Of Prayer (prayer to the dead, whether it's acceptable to pray to the Holy Spirit, what evidence we should expect for answered prayer, etc.)
The Evidence Of Biblical Prophecy (the dating of Daniel, why some prophecies aren't more specific, whether the New Testament is wrong about Old Testament passages like Isaiah 7:14 and Hosea 11:1, etc.)
The Afterlife (annihilationism, Limbo, near-death experiences, etc.)
The Canon Of Scripture (the Apocrypha, Jude's use of material from 1 Enoch, Biblical authorship, etc.)
What Early Non-Christians Said About Christianity (Jesus' existence, His miracles, what the early Christians believed about the veneration of images, etc.)
Baptism In The Bible And Church History (baptismal justification, infant baptism, baptism for the dead, etc.)
The Eucharist In The Bible And Church History (John 6, the eucharistic beliefs of the church fathers, paedocommunion, etc.)
The Relatives Of Jesus In The Bible And Church History (the genealogies of Jesus, the assumption of Mary, whether James was an unbeliever when the risen Jesus supposedly appeared to him, etc.)
The Death Of The Apostles (whether any of the apostles renounced the faith later in life, whether they died as martyrs, how they died, etc.)