The antidote to selfishness is true and sincere love.
Philippians 2:1-4 NIV
[1] Therefore if you have any encouragement from being united with Christ, if any comfort from his love, if any common sharing in the Spirit, if any tenderness and compassion, [2] then make my joy complete by being like-minded, having the same love, being one in spirit and of one mind. [3] Do nothing out of selfish ambition or vain conceit. Rather, in humility value others above yourselves, [4] not looking to your own interests but each of you to the interests of the others.
https://bible.com/bible/111/php.2.1-4.NIV
A wicked nature is devoid of love.