With accent marks:
Не так стра́шен чёрт, как его́ малюют.
The demon is not as scary as he is depicted.
This proverb is said to encourage the one who experiences excessive anxienty or fear of the unknown.
In the old days, parents were scaring there children saying that if they do not obey, the scary demon would take them. However, in fact, nobody has ever seen those demons anywhere.
This proverb teaches as not to be afraid of the constructs of our own mind or mind of others.
It is believed that the expression is primordially Russian, although later it passed into other European languages. In Russia, it has been known since the XVIII century.
Other Russian proverbs
Eggs don't teach the chicken.
The further into the forest, the more firewood is there.
With a darling, even a hut is a paradise.
In a healthy body, healthy mind.
Don't bring your set of rules in a foreign monastery
The eyes are scared, but the hands are doing.
Do not look at a given horse's teeth.
Some to the forest, some for firewood.