With accent marks:
Свя́то ме́сто пу́сто не быва́ет.
A holy place is never empty.
If a good place is empty, someone else immediately takes it.
For example, a position promising benefits and tempting prospects is rarely vacant - there are always those who want to take it.
Other Russian proverbs
Оne can not see the wood for the trees.
Hurry to much and you will make people laugh.
Measure seven times, cut one.
Forewarned is forearmed.
Eggs don't teach the chicken.
Time for business, an hour for fun.
The further into the forest, the more firewood is there.
The apple never falls far from the tree.