Contradiction with Ezekiel 34:6
This verse indicates a more accusatory tone towards shepherds for allowing the sheep to stray, showcasing a lack of seeking out the lost unlike the shepherd in Matthew 18:12.
Ezekiel 34:6: My sheep wandered through all the mountains, and upon every high hill: yea, my flock was scattered upon all the face of the earth, and none did search or seek [after them].
Contradiction with Matthew 10:14
Here, leaving those who do not receive the message is instructed, which contrasts the searching mentality portrayed in Matthew 18:12.
Matthew 10:14: And whosoever shall not receive you, nor hear your words, when ye depart out of that house or city, shake off the dust of your feet.
Contradiction with Proverbs 1:28
Suggests a futile seeking of wisdom when it's too late, contradicting the hope of finding the lost in Matthew 18:12.
Proverbs 1:28: Then shall they call upon me, but I will not answer; they shall seek me early, but they shall not find me:
Contradiction with Jeremiah 15:1
Implies that even with intervention, some will not be saved, contradicting the earnest search and hope seen in Matthew 18:12.
Jeremiah 15:1: Then said the LORD unto me, Though Moses and Samuel stood before me, [yet] my mind [could] not [be] toward this people: cast [them] out of my sight, and let them go forth.
Contradiction with Hosea 4:16
Compares Israel to a stubborn heifer, implying that some lost ones are not pursued, against the idea in Matthew 18:12.
Hosea 4:16: For Israel slideth back as a backsliding heifer: now the LORD will feed them as a lamb in a large place.
Paradox #1
Some might see a contradiction in the idea of leaving many to seek out one. It might be seen as risky or neglectful to leave the majority unprotected while focusing on only one individual. This can be viewed as showing favoritism or not valuing the larger group enough.