Final answer:
The source that stresses God as the source of life and hope and underscores the bilateral nature of the Sinai/Moses covenant is the Priestly (P) source.
Step-by-step explanation:
The source that emphasizes God as the source of life and hope and stresses the Sinai/Moses covenant as bilateral is D. Priestly (P). The Priestly source is known for a style that is formal and concerned with issues such as genealogies, dates, and rituals. It often emphasizes the theme of covenant and God's promise to humankind, portraying God as the source of life, law, and hope.
Within this source, a strong emphasis is placed on the worship of Yahweh and rigid adherence to the laws laid down at Sinai. The covenant with Moses is described as conditional, with blessings contingent upon Israel's obedience to God's laws.
By contrast, the other sources, such as the J (Yahwist) and E (Elohist), have different focuses and present different aspects of God's relationship with Israel. The Yahwist source often depicts God in more anthropomorphic terms, while the Elohist concerns itself more with prophetic visions and moral lessons. The Deuteronomist (D) focuses on law and Israel's need to follow God's commandments.