Note 6 at 1Co 2:11: Paul was saying that in the same way that no one really knows the deep thoughts of others except those individuals themselves, likewise, no one really knows the things of God except the Spirit of God. Therefore, people must be dependent upon the Holy Spirit to receive the wisdom of God in their lives.

Christians who have not received the baptism of the Holy Spirit (see note 1 at Ac 19:1) can have some revelation knowledge (see note 1 at Lu 2:26 and note 9 at Joh 6:45), but it will be limited. One of the greatest evidences that people have received the baptism of the Holy Spirit is the tremendous amount of God's wisdom that becomes available to them (see note 2 at Ac 2:16).