Do the Old and New Testaments agree about who God is?

²⁸And one of the scribes came, and having heard them reasoning together, and perceiving that he had answered them well, asked him, Which is the first commandment of all? ²⁹And Jesus answered him, The first of all the commandments is, Hear, O Israel; The Lord our God is one Lord: ³⁰And thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength: this is the first commandment. ³¹And the second is like, namely this, Thou shalt love thy neighbour as thyself. There is none other commandment greater than these. ³²And the scribe said unto him, Well, Master, thou hast said the truth: for there is one God; and there is none other but he: ³³And to love him with all the heart, and with all the understanding, and with all the soul, and with all the strength, and to love his neighbour as himself, is more than all whole burnt offerings and sacrifices. ³⁴And when Jesus saw that he answered discreetly, he said unto him, Thou art not far from the kingdom of God. And no man after that durst ask him any question.

⁴There is one body, and one Spirit, even as ye are called in one hope of your calling; ⁵One Lord, one faith, one baptism, ⁶One God and Father of all, who is above all, and through all, and in you all.