For us christians,  our purpose in life is to worship God. God created mankind to worship Him. Use your life for God's glory. Be an instrument of love and peace. Live a meaningful life and share it with the people you love. God did not create man for no purpose. God wants the people to enjoy his creation so that people will see the goodness of God. Use our lives as channel of blessings to others. Inspired them with our life story. Make people happy. Help the needy people. Share how God changes you and its effect on your life. Challenge other people.