Ephesians 2:5: “…made us alive with Christ even when we were dead in transgressions—it is by grace you have been saved.”
This Bible verse clearly states that we were dead in our sins. Our nature was sinful. There was nothing good about our thoughts, ways and actions. You know, if a person is dead you cannot revive him with aspirin. You cannot also kill the bad smell by simply sprinkling some perfume on him. Only a miracle working power of God can resurrect a person.
We often think that Jesus is some kind of moral example that could make us better. No, he did not come just to moralize you and teach you a better life. He came to take you out of hell, resurrect you from spiritual death, change your nature and make you a new creature. He is not a deodorant that tries to hide bad smell.
Jesus does not hide your bad nature. He changes it. He transforms you from inside out, not from outside in.
You cannot make an inner change by doing some outward actions: dressing nice, putting on make up, smiling and etc. No, you need an inner transformation. Jesus came to transform you. He came to make you a child of God. He came to save you. And He did that! Glory to God!