Om Swami
What is the purpose of life if I believe God created me?
Purpose follows belief: merge in the Divine
The aim of your life depends on what you believe. If you believe a God made you and gave you birth, your purpose is moksha, and you move toward it through the deeds, thoughts and words that advance you on your path.
If that is your belief, then naturally the purpose of your life is to attain moksha. The aim of your life is to attain that nirvana.