Resource mobilization refers to activities an organization undertakes to secure new financial, human, and material resources to advance its mission and ensure sustainability. It is important as it allows organizations to continue and improve services, scale up, and stay in business by generating new resources. The four main types of resources are physical, human, intellectual, and financial. Organizations achieve sustainability through programmatic, institutional, and financial stability, with strategic planning forming the basis for resource mobilization efforts. Challenges can be overcome through intelligence gathering, customizing mobilization to align with strategic plans, and establishing credibility through evidence-based results.