The Trinity Doctrine in the Book of Hebrews?
Hebrews is a comprehensive treatise about Christian doctrine. Since the Trinity doctrine is asserted to be the main doctrine of Christianity, we would expect Hebrews to include significant mention of the Trinity doctrine, if it is true.

In our series about what is stated concerning God the Father, his Son Jesus, and the holy Spirit in the various books of the New Testament, we examine all the relevant scriptures of each particular book. In this article, we will examine the Letter to the Hebrews, and discover powerful testimony about whether or not the doctrine of the Trinity is in Hebrews.