When he first came to Corinth, Paul preached nothing but Christ and Him crucified, which was in contrast to philosophy so prevalent at Corinth. Philosophy means the love of wisdom and leads the soul into reason and unbelief.
The apostle came in weakness and fear, not in the energy of the flesh, but in the power of the Spirit. We learn in the epistle to the Romans that our flesh is in the place of death, and only grace will do for life or service.
His desire was that their faith should not stand in the wisdom of men, but in God's power.
In these verses we see that Paul would have taught the assembly of the mystery, the deep things of God, the assembly's eternal place in the Father's house, and the precious things that accompany and are dependent upon those truths which are found in Ephesians. These should occupy us, but the state of the saints was such that they were not able to take these things in.
There are three special thoughts here: one, we have received by the Spirit; two, we speak by the Spirit; three, we discern by the Spirit.
Our natural minds and senses have no place in spiritual matters, for they only spoil, as was the case in Corinth. Divisions were made by the flesh and were of the flesh, but the spiritual mind has heavenly things before it, and in contrast to the natural man, it judges all things. "We have the mind of Christ."