Ps 33:6.
By the word of the Lord, the heavens were made,
and with the breath of His mouth, all their host.

God, the Word of the Lord, and the breath of His mouth created everything.

If God is personal, then His Word is personal, and His Breath/Spirit is personal.

The concept of the Trinity (not the word 'trinity' itself) is found in the HT. There is no difference between the HT and the GT. The only difference is here in that there is a developpement of theology (growth in the knowledge of God) from Genesis to Revelation.

The Church 'simply' used Greek philosophy to give words to the mystery of God, being Father, Word and the Spirit: One God, being a Unity and Community of Love between 3 Persons.

The origin and root of the concept of the Trinity is in the HT; also among Jews there is/was discussion on the nature of God as God, Word, and Spirit.

Greetings
Aad