Being Grateful to God
Some people are grateful to God, to the Supreme Soul, to someone they feel is up there. It can give them a huge psychological boost, help them survive difficult phases in life, give them the motivation to stay course among numerous other benefits. Those who believe in the existence of God, regardless of the religion they follow, have someone they can be grateful to God is not complete gratitude, though. Imagine being thankful to the mother who is never careless, indifferent or irresponsible towards her children. It is of little use. Far more important than being grateful to God is to be grateful to his children, his creation. This leads to the gratitude of the second type.
Being Grateful to Others
Love and gratitude are soulmates, happiness and harmony are their offsprings. It is not possible to be grateful unless you accept that someone has done something for you. If you feel, out of ego or ignorance, that it was your right, you will fail to feel grateful. Consequently, you will not experience any happiness, much less peace and bliss. Gratitude is not always about grand gestures, it may range from a sincere thank you to an act of extraordinary compassion.
The important thing to remember is that you must consciously express your gratitude without any expectations for reciprocation; it is hard but doable. True gratitude makes one generous, compassionate and infinitely loving. Practice of gratitude lends incredible emotional strength. If you are emotionally strong, you can succeed at anything, anything at all. Gratitude makes you emotionally pure and such purity in turn allows you to love unconditionally. Absence of anything dictates the value of its presence. When we express gratitude, when we feel it in our hearts, it helps us value what all we have in our lives. And that is a divine start to a good life.
Reference : A Million Thoughts. Om Swami.