Contradiction with 1 Timothy 5:22
This verse advises against being hasty in laying on of hands, which can be interpreted as advising caution in physical interactions, contrasting the open physical greeting in Thessalonians.
1 Timothy 5:22: Lay hands suddenly on no man, neither be partaker of other men's sins: keep thyself pure.
Contradiction with 2 John 1:10
This verse advises against greeting those who do not bring the correct teaching, which could contradict the more general greeting practice in Thessalonians.
2 John 1:10: If there come any unto you, and bring not this doctrine, receive him not into [your] house, neither bid him God speed:
Contradiction with Proverbs 27:6
This verse suggests that the kisses of an enemy are deceitful, which may warn against the practice of greeting kisses if they aren't sincere.
Proverbs 27:6: Faithful [are] the wounds of a friend; but the kisses of an enemy [are] deceitful. [deceitful: or, earnest, or, frequent]
Contradiction with Romans 16:16
Similar to 2 Corinthians 13:12, this verse reiterates the practice found in 1 Thessalonians 5:26, rather than contradicting it.
Romans 16:16: Salute one another with an holy kiss. The churches of Christ salute you.
Paradox #1
The contradiction or conflict could be that some people might find it uncomfortable or inappropriate to greet others in such an intimate way due to personal, cultural, or societal norms. This could lead to conflict if the expected greeting is not consistent with personal boundaries or cultural practices.