Check out my new book on depression and the fatherly attributes of God: https://www.amazon.com/dp/1650062478 Link to my children's book: https://www.amazon.com/dp/B08FP9NZNK The argument is generally the same no matter who you ask. From atheists to those of different religions to even different sects within Christianity, all observe that the term Trinity (nor any directly related word) is not found in Scripture. Many scholars agree that a reasoned concept of the triune God was not explicit in the minds of the New Testament authors even though John appears conscious of what has been termed “the problem of the Trinity.” The doctrine of the Trinity, like many other classical doctrines of Christendom, was organized and articulated after the writing of the NT. However, no other confession of faith is so foundational to historic Christian faith and to a mature biblical view. The knowledge of God as Holy Trinity is formed, structured, corrected, and (to some extent) limited by the witness of the Scripture.