The word of God is a seed. Now you must plant the seed in the right place and and create an atmosphere for it grow. A mango seed that was just planted will not germinate if there is no water. Also for the word of God to enter into your heart, sin has to be absent. Once there has been an entrance and a growth of the word of God, it will bring light and understanding.
'The entrance of thy word giveth light and understanding to the simple'
Psalm 119:130