Truth Unites: The Trinity is Apostolic
In this video Gavin Ortlund argues that the doctrine of the Trinity is a faithful explication of the teaching of the apostles.
Irenaeus on the Trinity: https://epublications.marquette.edu/cgi/viewcontent.cgi?article=1108&context=dissertations_mu
Truth Unites (www.truthunites.org) exists to promote gospel assurance through theological depth.