Jesus made it impossible to be a Child of God in the traditional Jewish way. Jesus preached the Laws and the requirement to follow the spirit of the Laws as well as the letter of the Laws. The previous posts about the Sermon on the Mount outlines these requirements. It was Paul who understood the real mission of Jesus. It was not to preach stricter adherence to the laws but to fulfill the stricter requirements of the Jewish Laws that called for the payment or punishment of sins. Jewish law required a blood sacrifice for the redemption of their sins. And Jesus came to pay that price!
It became Paul's task to explain that sacrifice to Jews and Gentiles alike. While studying with the disciples and others who knew Jesus, he began to develop the theology we now recognize as Christianity. The Gospel of John has the most concise explanation of this new faith. "...that whosoever believed in Him, shall be saved..."
(John 3:16). Paul developed it further in his letters, especially in his epistle to the Romans.
We humans simply can not do what the Laws required. We lust; we hate; we steal; we have other things as our gods; we are envious; in fact, we are incapable of "...being perfect..." We are all doomed to the fires of Hell as punishment for breaking the Laws of God. Those Laws require a fitting punishment. Think of the