Typically a strong person is thought to be one who is independent and self-sufficient, but Paul describes the strong Christian as one who subordinates his own preferences to the needs of those who are weaker in faith. The privilege of freedom comes with obligations. The key word here is "edify." The strong are to make concessions, but not simply for the convenience of the weak or even for peace in the fellowship. The strong are to bear the burdens of others so that eventually the others can leave the burdens behind. If strong Christians act so that others grow in spiritual understanding, then soon the concessions become unnecessary.
As our example, Christ showed patient sympathy for the limitations of others. But beyond a pattern of obedience, Christ also provides the power to conform to righteousness. In support of this dramatic conclusion, Paul quotes Old Testament psalms and prophets who were writing about the nature of God in anticipation of the fulfillment of the law through the Christ.
In the book of Romans, Paul describes the vast difference that the gospel makes in our outlook on life. We are not bound by what is humanly possible. We have more than our present experience. God works creatively through us, and the gifts from God are things that we are not likely to get any other way.
Verse 13 concludes this section with a benediction blessing that sums up the new life in Christ. "May the God of hope fill you with all joy and peace in believing, so that you may abound in hope by the power of the Holy Spirit."