Was Jesus good?

Why is it so challenging for us to accept what Jesus said about himself?
Why do you call me good?, Jesus answered. No one is good, except God alone. Luke 18:19

Could it be because, deep down, we also want to be good, and if not even Jesus said he was, then what is left for us?

See what the Bible reveals about the human being:
The Lord saw that the wickedness of man had increased on the earth and that every inclination of the thoughts of his heart was only evil all the time. Genesis 6:5

Now see also what the apostle Paul says about himself:
I do not understand what I do. For I do not do what I want, but what I hate. Romans 7:15
I know that nothing good dwells in me, that is, in my flesh. For I have the desire to do what is good, but I cannot carry it out.
For I do not do the good I want, but the evil I do not want to do, that I keep on doing. Romans 7:18,19

Since childhood, we were taught that we should try to be good. Is that really right, for Christians? Or is it just a deception from the craftiest of all? See what he said to himself:
I will ascend to heaven; … I will ascend above the tops of the clouds and I will be like the Most High. Isaiah 14: 13-14
And, as in his conversation with Eve: … you will be like God… Genesis 3: 5

Is wanting to be like God, wanting to be good, evil?
Why is it that what the Bible revealed approximately 2,000 years ago, we still cannot fit into our understanding?

How do you understand this?