Mark 12:28-29 reads
One of the teachers of the law came and heard them debating. Noticing that Jesus had given them a good answer, he asked him, ‘Of all the commandments, which is the most important?’
29 ‘The most important one,’ answered Jesus, ‘is this: “Hear, O Israel: the Lord our God, the Lord is one.[e] 30 Love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength.”
the footnote [e] is very interesting:
This is a million miles from the idea of God as three co-equal divine persons (or Lords, plural), Father, Son, and HS, each considered God but each remaining distinct from the other two. In sum, Jesus was a Jewish monotheist not a trinitarian Christian. Later tradition has swamped Jesus’s creed.