The United States on Monday will honor Dr. Martin Luther King, the country's most revered civil rights leader.

King’s powerful words in fighting for racial equality have had a lasting impact on the world and continue to inspire people. A 1999 Gallup poll showed that that only Mother Teresa was considered a more admired person than Dr. King in the 20th century.

In honor of MLK Day, here are 21 inspiring quotes by Dr. King, compiled from A-Z Quotes and Goodreads.

1. “Returning violence for violence multiplies violence, adding deeper darkness to a night already devoid of stars.”

2. “Faith is taking the first step even when you can’t see the whole staircase.”

3. “There is no gain without struggle.”

4. “Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that.”

5. “Forgiveness is not an occasional act, it is a constant attitude.”

6. “If you can’t fly then run, if you can’t run then walk, if you can’t walk then crawl, but whatever you do you have to keep moving forward.”

7. “If I cannot do great things, I can do small things in a great way.”

8. “The ultimate measure of a man is not where he stands in moments of comfort and convenience, but where he stands at times of challenge and controversy.”

9. “It does not matter how long you live, but how well you do it.”

10. “The silence of the good people is more dangerous than the brutality of the bad people.”

11. “Those who love peace must learn to organize as effectively as those who love war.”

12. “We may have all come on different ships, but we’re in the same boat now.”

13. “Occasionally in life, there are those moments of unutterable fulfillment which cannot be completely explained by those symbols called words. Their meanings can only be articulated by the inaudible language of the heart.”

14. “Love is the most durable power in the world. This creative force is the most potent instrument available in mankind’s quest for peace and security.”

15. “Everybody can be great...because anybody can serve. You don’t have to have a college degree to serve. You don’t have to make your subject and verb agree to serve. You only need a heart full of grace. A soul generated by love.”

16. “Never, never be afraid to do what’s right, especially if the well-being of a person or animal is at stake. Society’s punishments are small compared to the wounds we inflict on our soul when we look the other way.”

17. “Not everybody can be famous but everybody can be great because greatness is determined by service.”

18. “The time is always the right time to do the right thing.”

19. “Those who are not looking for happiness are the most likely to find it because those who are searching forget that the surest way to be happy is to seek happiness for others.”

20. “We must accept finite disappointment, but never lose infinite hope.”

21. “Nothing in the world is more dangerous than sincere ignorance and conscientious stupidity.”

Martin Luther King
Black American civil rights leader Martin Luther King (1929 - 1968) addresses crowds during the March On Washington at the Lincoln Memorial, Washington DC, where he gave his 'I Have A Dream' speech. Getty Images/ Central Press