Excerpt   from an article by Iasos, the New Age musician   Try the angel exercise at the end. It works! 

   There is the universal law that Beings in one dimension can not assist beings on another dimension unless the request or invitation comes from the dimension wishing to receive the   assistance.
To a great extent this leaves many angels with their "hands tied", with respect to helping humans.  They live but to serve. They love to serve. They evolve by serving. It makes them happy to  serve. But you have to invoke them. That means, they cannot help you unless you call on them  Why not test them right now, while you read this? Think of some divine quality that you really need or would like more of.  Then silently in the depths of your Heart, request and invite the appropriate angels to administer   this quality to you. You can even make your request more specific: Ask for a "heart beam" - with one angel in front of you facing you, and another angel behind you, also facing you. Sense
 them create a pillar of Light connecting their Hearts, with this Light Beam passing directly through your Heart! Feel this for just a few moments....... then you have a sense of the magical assistance that is always lovingly available to you - - just a thought away.