When Paul wrote in 1 Corinthians 2:2, “For I determined not to know anything among you except Jesus Christ and Him crucified,” he did not mean that was all he taught or all that he wanted the Corinthians to know. But Christ and Him crucified is the fountain from which all the blessings of God flow to those who believe in Christ. The things which God has prepared for those who love Him were provided by Jesus at the cross (cf. Rom. 8:32).
In 1 Corinthians 2:9-16, we find four truths about these things which God has prepared for us: You would never have discovered these things on your own (vs. 9). The Holy Spirit revealed these things to us (vv. 10-11). God gave us the Holy Spirit so that we might know or understand these things (vs. 12). Paul (and the other apostles) spoke these things in words taught by the Holy Spirit (vs. 13).