“Verily, what I fear most for you is the lesser idolatry.” And he elaborated, “It is showing off. Allah the Exalted will say to them (who show off), on the Day of Resurrection when the people are being rewarded for their deeds: Go to those whom you wished to show off in the world and look for your reward with them.”(Musnad Ahmad Hadith 23119)
The above Hadith is a good reminder of how sincerity in our acts of worship is extremely important. Even the best actions can be a source of regret on the Day of Judgement if done with the wrong intention. In the following video, Shaykh Wasim Kempson talks about one of the things we can do to maintain sincerity in our Ibaadah.