For I determined not to know anything among you (ου γαρ εκρινα τ ειδενα εν υμιν). Literally, "For I did not decide to know anything among you." The negative goes with εκρινα, not with τ. Paul means that he did not think it fit or his business to know anything for his message beyond this "mystery of God."

Save Jesus Christ (ε μη Ιησουν Χριστον). Both the person and the office (Lightfoot). I had no intent to go beyond him and in particular, and him crucified (κα τουτον εσταυρωμενον). Literally, and this one as crucified (perfect passive participle). This phase in particular (1 Corinthians 1:18) was selected by Paul from the start as the centre of his gospel message. He decided to stick to it even after Athens where he was practically laughed out of court. The Cross added to the σχανδαλον of the Incarnation, but Paul kept to the main track on coming to Corinth.