Answer:
The Enlightenment thinker who most influenced Thomas Jefferson with his belief that government is obliged to serve people by protecting life, liberty, and property was John Locke.
Locke believed that government derives its power from the consent of the governed and therefore must protect the rights of its citizens, including the right to life, liberty, and property.
Jefferson incorporated these ideas into the Declaration of Independence, which declared that governments are instituted to secure the rights of life, liberty, and the pursuit of happiness.