(Read Matthew 26:1-13.)
Mary anoints Jesus and the disciples think it's a waste, saying the cost of the perfume could have been spent on more practical matters. While not denigrating the need to care for the poor, Jesus upholds Mary's action of worship.
Many people today see religion and worship as a waste of time, saying that your offering can be better spent elsewhere other than the church. Your time can be better spent elsewhere than in church or reading your Bible or doing whatever else religious people do. Religion isn't practical, they say.
But Jesus holds Mary up as an example. It is important to simply spend time in adoration of Christ. This time spent with Him, and meditating on Him, is what fuels and charges us and gives us direction for our daily, "practical" tasks.