that's depend on what you mean by this phrase (for relationship or for taking chances or choices) but in general you can say الابتعاد ليست للضعفاء وانما للشجعان (الأقوياء). if you tell me for what you will say this phrase I will give you better translation for each statement

that quote means "البعد (الفراق) لن يجعلنى جبان ولكنه سيزيدنى جرأة"

Distance is not for the fearful, it is for the bold. ليست الغربة او البعد للجبان ولكن الجرىء هو الذى يقدر على ذلك This means that long-distance or alienation is not estimated by the cowardly but bold is the one who bears the trouble in exile or in distance from family and loved ones and friends

is it proverb ?

Not sure what you mean by "distance" here, but you can say: ليس للجبناء، بل للشجعان to mean "Not for the cowards, but for the brave". Then insert whatever word you like in front of that phrase and you've got your sentence.