Although only the foundation was laid by me, the complete design of the building has already been given there.
In material buildings, the foundation indicates only the outward form of the building. In spiritual buildings it is not so.
Here the foundation also indicates the plan of the whole building, its character, and the materials from which it must be built.
Whoever undertakes to build must understand all this well. Then he must raise the building with all attention: let him take heed how he builds.
The reason for such speech is explained afterward. Here the Apostle only fixes attention on this point.
He wants the one who has undertaken to raise the building to reflect: has he rightly understood what he must do and how he must do it?
He has begun the building on a ready foundation, and on one that indicates everything.
After founding the Church in Corinth, the Apostle went elsewhere. After him Apollos came and continued the building of the Church.
He continued the work wholly in the spirit of the holy Apostle Paul. Therefore he acted rightly and blamelessly. Saint Paul does not have him in view.
But when Apollos also departed from there, certain local wise men rose up. They were more capable, more educated, and more talkative than others.
They came forward as leaders for the lesser brethren. Paul aims at them.
At the same time, every Christian is a small image of the Church. Each also received from the Apostle the foundation for the building of salvation within himself by faith in the Lord.
Therefore each one had to see in this a good reminder for himself: take heed how you build.
Saint Chrysostom says, "Here, it seems to me, he turns them toward the struggles of life." Oecumenius continues: "He calls them to a fitting life, naming each one's activity a building."
"Let each one take heed how he builds upon the foundation laid, that is, having faith and Christ Himself, so that he may do good works."
In the words "as a wise master builder," the thought is not that he calls himself wise. There is only a comparison.
When a wise master builder lays a foundation, he lays the proper, firm, and best foundation. Such a foundation I also laid, or rather, God laid through me.
For everything I do, I do according to the grace given to me. The force of the thought is not on the wisdom of the one laying the foundation.
It is on the foundation's firmness, or on its unchangeability. It is on the fact that a foundation has been laid that cannot be changed, because it is the only one in the spiritual building.
He speaks about this immediately. But even if one accepts that he called himself wise, this still does not mean that "he exalts himself."
Rather, "he offers them an example and shows that it belongs to the wise man to lay one, and only one, foundation."
"And see how he observes humility even here. Having called himself wise, he did not ascribe this to himself."
"First he handed himself over entirely to God, and only then called himself this: 'according to the grace of God given to me,' he says. At the same time he teaches that everything is God's" (Chrysostom).