Moreover. But, (de). In addition to what I have said; or in that which I am now about to say, I make known the main and leading truth of the gospel. The particle de is "strictly adversative, but more frequently denotes transition and conversion, and serves to introduce something else, whether opposite to what precedes, or simply continuative or explanatory." -- Robinson. Here it serves to introduce another topic that was not properly a continuation of what he had said, but which pertained to the same general subject, and which was deemed of great importance.
I declare unto you. gnwrizw. This word properly means, to make known, to declare, to reveal, (Lk 2:15 Rom 9:22, Rom 9:23; ) then to tell, narrate, inform, (Eph 6:21 Col 4:7, Col 4:9; ) and also to put in mind of, to impress, to confirm. See "1Cor 12:3".
Here it does not mean that he was communicating to them any new truth, but he wished to remind them of it; to state the arguments for it, and to impress it deeply on their memories. There is an abruptness in our translation which does not exist in the original. Bloomfield.
The word here means the glad announcement, or the good news about the coming of the Messiah, his life, and sufferings, and death, and especially his resurrection. The main subject to which Paul refers in this chapter is the resurrection; but he includes in the word gospel, here, the doctrine that he died for sins, and was buried, as well as the doctrine of his resurrection. See 1Cor 15:3, 1Cor 15:4.
Which I preached unto you. Paul founded the church at Corinth, Acts 18:1, seq. It was proper that he should remind them of what he had taught them at first; of the great elementary truths on which the church had been established, but from which their minds had been diverted by the other subjects that had been introduced as matters of debate and strife. It was fair to presume that they would regard with respect the doctrines which the founder of their church had first proclaimed, if they were reminded of them; and Paul, therefore, calls their attention to the great and vital truths by which they had been converted, and by which the church had thus far prospered. It is well, often, to remind Christians of the truths which were preached to them when they were converted, and which were instrumental in their conversion. When they have gone off from these doctrines, when they have given their minds to speculation and philosophy, it has a good effect to remind them that they were converted by the simple truths that Christ died, and was buried, and rose again from the dead. The argument of Paul here is, that they owed all the piety and comfort which they had to these doctrines; and that, therefore, they should still adhere to them as the foundation of all their hopes.
Which also ye have received. Which you embraced; which you all admitted as true; which were the means of your conversion. I would remind you that, however that truth may now be denied by you, it was once received by you, and you professed to believe in the fact that Christ rose from the dead, and that the saints would rise.
And wherein ye stand. By which your church was founded, and by which all your piety and hope has been produced, and which is at the foundation of all your religion. You were built up by this, and by this only can you stand as a Christian church. This doctrine was vital and fundamental. This demonstrates that the doctrines that Christ died "for sins," and rose from the dead, are fundamental truths of Christianity. They enter into its very nature; and without them there can be no true religion.