Humanity can’t be good on their own:
• Good works alone will not get us into the Kingdom
• Because of the curse of sin
• Through the first man Adam (scripture reference)
• But Jesus Christ “the second Adam” (reunited us with God)
1 Corinthians 15:45-47: And so it is written, The first man Adam was made a living soul; the last Adam was made a quickening spirit.46 Howbeit that was not first which is spiritual, but that which is natural; and afterward that which is spiritual.47 The first man is of the earth, earthy; the second man is the Lord from heaven.
Also, see Gen 3:15: