1Co 13:6 Rejoiceth not in iniquity, but rejoiceth in the truth; (KJV)
1Co 13:6 Love never rejoices at evil, but rejoices in the triumph of Truth; (TCNT, Twentieth Century NT)
1Co 13:6 Is never glad when wrong is done, but always glad when truth prevails; (Williams NT)
1Co 13:6 rejoices not in wickedness, but rejoices in the truth; (Sawyer NT)
1Co 13:6 It is not glad about injustice, but rejoices in the truth. (NET Bible)
1Co 13:6 rejoiceth not in unrighteousness, but rejoiceth with the truth; (ASV, American Standard Version)
Each English translation of 1 Corinthians 13:6 presented above contributes additional insight drawn from what the translators saw in the underlying Greek text.
Taken together, love does not rejoice in iniquity, or evil, when wrong is done, in wickedness, in injustice, or unrighteousness.
Love rejoices in the triumph of truth, is glad when truth prevails, rejoices in the truth.
Considering an opposite trait, the opposite of truth is untruth or a lie.
Hedging the truth by telling a lie is not compatible with love, and may bring very dire eternal consequences:
Rev 21:8 But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death.
To Dig Deeper:
Read the cross references given in The Ultimate Cross Reference Treasury for 1 Corinthians 13:6 which I share below.
1 Corinthians 13:6
Rejoiceth not. FS155F, +Gen 4:7, Gen 9:22, +*Lev 19:17, 1Sa 23:19, 20, 21, 2Sa 4:10, 11, 12, Psa 10:3; +*Psa 15:4; Psa 35:15; *Psa 119:136; *Psa 119:139, Pro 2:14; *Pro 14:9; +*Pro 24:17 with Mat 5:44, Jer 9:1; Jer 11:15; Jer 13:17; Jer 20:10, Hos 4:8; Hos 7:3, Mic 7:8, *Luk 19:41; *Luk 19:42; Luk 22:5, *+Rom 1:32, Php 3:18, **2Th 2:12, Rev 11:10.
iniquity. or, unrighteousness. +*Rom 1:18.
rejoiceth. Exo 18:9, Jos 22:22-33, Joh 20:20, *Act 11:23, Rom 12:9, 2Co 7:9, 10, 11, 12, 13, 1, 15, 16, Php 1:4; Php 1:18; Php 2:17, 18, 1Th 3:6, 7, 8, 9, 10, *2Jn 1:4, 3Jn 1:3, 4.
in the truth. or, with the truth. 1Co 12:26.