NOTES for Co1 13:4-7
Even before the coming of Christ, it was commonly accepted that love for God and neighbor is the whole essence of the 'Torah and the Prophets,' as Scripture was called in those days. But in the context of Christian revelation the concept of love received different, new content. Of course, love, at least in the biblical sense of the word, had already meant above all an attitude toward a person that desired only good for him, and an interaction with him that would be for his good.
Biblical love has little in common with sympathies or antipathies, with whether a neighbor is humanly pleasant or unpleasant to someone, or even with how that neighbor behaves. Even if he becomes an enemy, he must not be hated, avenged, or harmed, though at times such a person must be stopped if he is trying to harm someone, and stopped firmly enough. But even then love for neighbor includes the possibility of giving him a new chance to restore normal relationships with those to whom he had been an enemy, if there is any ground at all to hope that such restoration is possible.
All this belonged to the ideas of righteousness and of the righteous person's relation to neighbors that had formed before the Christian era. And Paul insists that everything said remains in force for Christians. But he also speaks of more. Before, righteousness was a possibility that could either be realized or not realized in the life of a particular person.
That particular person could fall short of the fullness of righteous life, yet everything he did on the path of righteousness still had its meaning. Even if a person could not show the fullness of love, he could at times still say of himself that he had moved in the right direction and had managed to achieve this or that. Paul says: all this is excellent, but if one does not go to the end, if one does not learn to build relationships of love with neighbors, everything else is worth nothing.
In the Kingdom only relationships of love are possible; if they are absent, if a person has not learned to build such relationships with neighbors, he cannot enter the Kingdom. Not because someone wants to punish him or despises his achievements, but because without such a skill it is impossible to live the life of the Kingdom. That is why the apostle speaks of love, which alone gives meaning to all other achievements: without love a person will still remain outside the Kingdom. With all his achievements.