diá, "thoroughly back-and-forth," which intensifies
krínō, "to judge"
kri means 'separation'
I like to bring a spiritual dimension to the interpretation of this word in 1 Corinthians 11:29, i.e., diakrínō involves deep thinking to analyze even to the point of the spiritual dimension.
1 Corinthians 12:10 to another miraculous powers, to another prophecy, to another distinguishing [diakriseis] between spirits, to another speaking in different kinds of tongues, and to still another the interpretation of tongues.
Jude 1:9 But even the archangel Michael, when he was disputing [diakrinomenos] with the devil about the body of Moses, did not himself dare to condemn him for slander but said, "The Lord rebuke you!"
The context in 1 Corinthians 11:29 is the Lord's Supper. Spiritually speaking, in
John 6:54 Whoever eats my flesh and drinks my blood has eternal life, and I will raise them up at the last day.
John 6:63 The Spirit gives life; the flesh counts for nothing. The words I have spoken to you--they are full of the Spirit and life.
For those who eat and drink without recognizing the deep truth of the spiritual reality of the body of Christ eat and drink judgment on themselves.
Hebrews 4:12 For the word of God is alive and active. Sharper than any double-edged sword, it penetrates even to dividing soul and spirit, joints and marrow; it judges the thoughts and attitudes of the heart.
Disclaimer: I am not talking about transubstantiation.