You are indeed searching for the truth kudos. Have no hesitation in regards to questioning. Remember the Jewish people followed faithfully their religious leaders without question. The problem we have today is knowledge is at our fingertips. People when they question a scriptural discrepancy don't just accept responses like "Oh GOD changed his mind about the food thing" Oh yeah and that commandment about not causing human death that GOD wrote with his finger, again he changed his mind when he told Moses to stone people. We always have to remember that all scripture is written by a human and inspired by GOD or Jesus (with the exception of the 10 Commandments which were written by the finger of GOD) and as humans we are imperfect so we cannot expect perfection in our scriptures. Their imperfection however does not remove their validity but you must always question does this passage follow the 10 commandments or the teachings of Jesus the Christ the WORD of GOD. To canonize something means to agree to classify its authenticity. Yes there are many scriptures and you need to look at all scripture you read under the same light. Is this information from GOD or Jesus.
The Jewish religious leaders put Jesus to a test, they too knew scripture and in the scriptures GOD wrote with his finger "you shall not cause human death" but Moses claimed you should stone a woman who commits adultery. They were certain they had Jesus, he would either have to break the law of Moses or GOD's law here's the passage:
John 8: 1 but Jesus went to the Mount of Olives. 2 Early in the morning he came again to the temple. All the people came to him, and he sat down and taught them. 3 The scribes and the Pharisees brought a woman who had been caught in adultery, and placing her in the midst 4 they said to him, “Teacher, this woman has been caught in the act of adultery. 5 Now in the Law, Moses commanded us to stone such women. So what do you say?” 6 This they said to test him, that they might have some charge to bring against him. Jesus bent down and wrote with his finger on the ground. 7 And as they continued to ask him, he stood up and said to them, “Let him who is without sin among you be the first to throw a stone at her.” 8 And once more he bent down and wrote on the ground.9 But when they heard it, they went away one by one, beginning with the older ones, and Jesus was left alone with the woman standing before him. 10 Jesus stood up and said to her, “Woman, where are they? Has no one condemned you?” 11 She said, “No one, Lord.” And Jesus said, “Neither do I condemn you; go, and from now on sin no more.”