No one lights a lamp and then covers it with a bowl or hides it under a bed. A lamp is placed on a stand, where its light can be seen by all who enter the house.
In the beginning God created the heavens and the earth. The earth was formless and empty, and darkness covered the deep waters. And the Spirit of God was hovering over the surface of the waters.
But when you pray, go away by yourself, shut the door behind you, and pray to your Father in private. Then your Father, who sees everything, will reward you.