The ancient, Biblical doctrine of the Trinity is not hard to express or hard to understand - 𝐢𝐧 𝐭𝐡𝐞 𝐰𝐨𝐫𝐝𝐬 𝐚𝐧𝐝 𝐞𝐱𝐩𝐫𝐞𝐬𝐬𝐢𝐨𝐧𝐬 𝐨𝐟 𝐭𝐡𝐞 𝐁𝐢𝐛𝐥𝐞.
Or, at least, nobody in the Bible seems to think it is especially weird or complicated that the Father, Son and Spirit are all equally the one God together - that the Father sends His Son/Angel/Word in the power of the Spirit to accomplish all His will.
When Moses or Isaiah or John or Paul speak like that, they don't think it is necessary to provide a complex footnote to explain or clarify what they are saying.
They genuinely seem to speak as if these truths are obvious, clear and easy to grasp.
Later, when the attempt is made to express these simple Biblical truths in more philosophical terms and to try to explore HOW it is that the Father, Son & Spirit are all equally the one God together and how they all act together in all things... well, then it really does lead to many complex footnotes and detailed clarifications, especially because the task is done to exclude error and answer enemies rather than to positively preach the foundational Biblical truth.
Some of us have been doing a fairly deep dive into the background and proceedings of the Council of Nicaea - and then later in the year we will be doing similar careful analysis of the later ecumenical councils.
https://thechristcentredcosmiccivilisation.buzzsprout.com/
The simple truth of the Trinity is expressed in all kinds of beautiful ways in the Bible.
* The Most High sends His divine Angel with His Almighty Spirit.
* God speaks His divine Word by His divine Breath.
* The Father always sends His Son to do His will in the power of the Spirit.
* The Ancient of Days, pouring forth the divine Fire, places all authority and power in the Son of Man who approaches Him as an equal.
* The LORD who is the first and the last declares "The Sovereign Lord has sent me, with His Spirit." (Isaiah 48:16)
We might express this in words that try to stick close to the words of the Bible or "everyday words" that try to capture that same basic truth...
but perhaps let's not overdo the more conceptually complex ideas that were formed not only to express the truth but also to push away falsehood.
Whatever it means to be God... the Father, Son and Spirit are equally that together.
Jesus only ever does the will of His Father in the power of the Spirit.