O Allah, show us the truth as true, so that we may pursue it; and show us the false as false, so that we might avoid it; and do not leave the matter confusing for us, lest we proceed on a whim.
Allahumma salli ala Muhammad wa ala alihi wa sahbihi wa sallim.
Alhamdulillahi rabbil Alameen. Ameen.
This dua is attributed to Abu Bakr as-Siddiq (radiallahu anhu)