、。
It's easy to tell good from bad.
Literal
Good things, bad things [object-を] distinguish [nominalizer-のは] easy [copula-だ].
良い事 and 悪い事 as paired abstract nouns (事 rather than 物 since these are abstract 'things'). 区別する ('to distinguish, differentiate'). 簡単 (basic na-adjective for easy). The cleft structure ~のは~だ.