Many new and seasoned practitioners are curious about deity worship and how it works. Some people feel drawn to one deity or another, some will say their deity chose them, and others will apply the appropriate deity that they feel has the right energy for their candle-burning spell.
Much like energizing a mojo bag, the more energy you put into your relationship with a deity, the more they will give back. Many find their deity was the "missing component" needed to better focus their energy into more successful spell work.