It is my understanding that Jesus's teachings, in part, were based on those teachings of the Greek school of Cynicism. The Cynics stressed that Virtue was more important than accumulating wealth. The Greek philosopher, Socrates, seemed to echo this Greek idea in claiming "his poverty, was proof of his pursual of virtue rather than accumulating wealth." That is to say, that Jesus' teachings were derived from Greek schools of Philosophy, circa 400 BC through 33 AD.
A famous New Testament scenario has a wealthy young Jew asking Jesus "what he can do to improve himself" and Jesus tells him, "give all your wealth away and be like me." The wealthy man turns away upon hearing this.
Jesus is portrayed as being poor, having no place to rest his head. Jesus' message of pursuing righteousness, or virtue, instead of the accumulation of wealth is not a Jewish concept, it appears to be Hellenistic Greek (Socratic and Cynic). By contrast the Old Testament teaches that material wealth is a sign of God's blessings bestowed upon his followers, whereas poverty is a sign of God's displeasure. Christianity arose in a Hellenistic World, and it is understandable that it assimilated Hellenistic Greek notions about the importance of virtue over material wealth.
The Old Testament teaches that God will not allow a righteous man be overcome by his enemies, the righteous will destroy his enemies! Just the opposite is taught by Christianity: Allow evil men to accomplish your death (like Jesus did), remain loyal to God, and to virtue, your reward from God, will be after death, in a resurrection of the dead. In the Old Testament the Righteous achieve victory over their enemies in their lifetimes, not after their deaths.
All this is to say, for me, the New Testament teachings of Jesus are from Greek schools of Philosophy and are opposed to Old Testament teachings.
I found the following work to be very influential in shaping my understanding that Jesus had accepted Cynic teachings: F. Gerald Downing. Cynics and Christian Origins. T & T Clark, Edinburgh. 1992. pp. 377.