Our mind is like a magnet which draws unto itself its one like, type and kind.
For many of us, the power of attraction in our mind is too weak to meet the demands. A magnet can only draw to itself in proportion to its own power; our mental magnet is greatly reduced in strength by our worries and our fears, and our inflow of good is slowly closed off or muted. If our mental force becomes too weak, we may even repel what little good is trying to reach us.
Just as we can charge a magnet with electric energy to build up its power of magnetism, our mind can be charged with mental energy that builds up our power of attraction.