Are you saying CC believes the thief on the cross was not baptized, therefore Jesus must have been a liar?
The thief was under the Law. Jesus had earlier commanded the leper “to go thy way, shew thyself to the priest, and offer the gift that Moses commanded, for a testamony unto them”. Matt. 8:4 The thief was condemned to death and could only repent to the ‘great high priest’ himself.
Regardless of the CoC position on the repentant thief, the Word says that a “testament is of force after men are dead: otherwise it is of no strength AT ALL while the testator LIVETH.” Heb. 9:17 This ‘new and living way’ began when the Holy Ghost was initially poured out.