Final answer:
The primary reason to teach the gospel, as per Elder Dallin H. Oaks, is to share God's love and grace, emphasizing the tenets of love, unity, and righteousness, and addressing the root of societal issues through a spirit of togetherness.
Step-by-step explanation:
The primary reason we teach others the gospel, as articulated by Elder Dallin H. Oaks, is not to bring people into the Church, increase the membership of the Church, or persuade people to live better lives. According to the ethos of Christian teachings and the legacy of the Great Commission to preach the gospel, the principal purpose lies in sharing the love and grace of God. The message conveyed accentuates the importance of love, unity, and righteousness, as encapsulated in the Sermon on the Mount found in Matthew 5. It emphasizes being peacemakers, seeking righteousness, and not hiding our light. Moreover, it suggests that the lack of love and care is at the root of many societal issues. Thus, teaching the gospel should be fundamentally about imparting the love of God and fostering a communal spirit of togetherness.