The correct option is D. if the matter was not of God it would fail. Detailed Explanation:

1. Context of Gamaliel's Advice:
2. Gamaliel was a respected Pharisee and a member of the Sanhedrin, the Jewish ruling council. In the Book of Acts (Acts 5:34-39), he addresses the council after the apostles had been arrested for preaching about Jesus. The council was considering what to do with the apostles, who were gaining a significant following.
3. Gamaliel's Reasoning:
4. Gamaliel advised the council to be cautious in their actions against the apostles. He pointed out that if the movement led by the apostles was merely a human endeavor, it would eventually fail on its own. He referenced historical examples of other movements that had risen and fallen, suggesting that if the apostles' message was not divinely inspired, it would not endure. This reasoning reflects a deep understanding of the nature of divine intervention versus human ambition.
5. Why Option D is Correct:
6. The essence of Gamaliel's argument is that if the apostles were truly sent by God, then their mission would succeed regardless of human opposition. Conversely, if it was not of God, it would naturally come to nothing. This perspective emphasizes a faith-based approach to discernment, suggesting that divine will ultimately prevails over human efforts to suppress it.

Why the Other Options are Incorrect:

• Option A: He feared the people:
• While it is true that Gamaliel recognized the potential backlash from the people if the apostles were harmed, his primary argument was not based on fear. Instead, he focused on the implications of divine authority and the futility of opposing God's will. Thus, this option is weaker because it reduces Gamaliel's wisdom to mere fear rather than a thoughtful consideration of divine sovereignty.
• Option B: He believed what the apostles said:
• There is no explicit indication in the text that Gamaliel fully believed the apostles' message. His advice was more about caution and the possibility of divine involvement rather than a personal belief in their claims. This option is incorrect because it assumes a level of faith in the apostles' message that is not supported by the narrative.
• Option C: He saw the miracle they had done:
• While Gamaliel may have been aware of the miracles performed by the apostles, his advice did not hinge on witnessing these miracles. His argument was more philosophical and strategic, focusing on the implications of opposing a movement that could be of divine origin. Therefore, this option is incorrect as it misrepresents the basis of his counsel.

Summary of Key Points:

• Gamaliel advised the council to release the apostles based on the principle that if their mission was of God, it would succeed; if not, it would fail.
• His reasoning reflects a deep understanding of divine authority and the futility of opposing God's will.
• The other options (A, B, C) misinterpret Gamaliel's motivations and the basis of his advice, focusing on fear, belief, or miracles rather than the overarching theme of divine sovereignty.

This understanding of Gamaliel's advice is crucial for grasping the dynamics of faith, authority, and the early Christian movement in the context of the New Testament.