This central doctrine of the Christian religion is not a biblical concept which a Bible reader can compare and validate or negate. A surfer would notice that the task of finding the TEXT of the Doctrine on the Internet is like finding a needle in the hay stick. One God in three Persons - the Father, the Son and the Holy Spirit. Such is the Father, such is the Son and such is the Holy Spirit. None is Greater than the other.
None is Before or After in time than the other.
None is dissimilar in Substance than the other. Jesus did admit that to be the case.