When it comes to speaking of having light in you, that refers to the light that is coming down from your I AM presence, through your higher Christ self, and down into your being through and out your heart chakra. The part of the heart chakra the light comes through is called many things such as the High Heart Chakra or the secret chamber of the heart. No matter what someone calls it what it is and the importance of it is still the same.
The secret chamber of the heart is the opening that allows the light of God to come into your being.
This does not mean every one has light in them because often that light, starting out pure, is filtered through our being and what we are and the things we do filters and changes the light. For most of humanity the purity of light is but a trickle once it is filtered.
That filtering is called HUMAN LIGHTHOUSE FILTERS
Many work on raising their vibrations but must understand that when it comes to trying to hold more pure light, being more of your God self and less of your lesser human self, that all the work done through meditation, working on chakras, etc could garner little advancement if there is still a lot of filtering of the light. You may work hard to increase that light and things you do, and take for granted, such as worrying, being angry, being frustrated, being biased, etc. could cancel out all the benefits you think you should be gaining. To spend hours in prayer just to then spend the rest of the day suffering the lesser human condition is like cancelling out all that prayer should have benefited you.
You can gain much benefit from a day where maybe you do not pray but try to not filter the light. A day spent being pleasant, not worrying about the things around you that you can not control, not getting angry and being more passive, will benefit you much and make any praying or decreeing much more effective.