These scriptures you have posted are right about what they are speaking about. However what they are speaking about is in verse 10. If you'll read from verse 10 d0wn you would get a much clearer picture of what is really being said.1 Cor 2 (HCSB)
13 We also speak these things, not in words taught by human wisdom, but in those taught by the Spirit, explaining spiritual things to spiritual people. 14 But the unbeliever does not welcome what comes from God’s Spirit, because it is foolishness to him; he is not able to understand it since it is evaluated spiritually. 15 The spiritual person, however, can evaluate everything, yet he himself cannot be evaluated by anyone.
Unbelievers don't "get it" because they are not born of the Spirit.
The gospel is not the deep things of God. Understanding of the gospel Salvation was sent to the gentiles and they have heard and understood it . It's the New Testament.
MB