Contradiction with Matthew 7:7
While Amos 8:12 speaks of a famine of hearing God's words, Matthew 7:7 encourages seeking and promises that those who seek will find, presenting a contrast in availability of God's word.
Matthew 7:7: Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you:
Contradiction with Isaiah 55:6
Amos 8:12 suggests a time will come when people will seek God's word but not find it, whereas Isaiah 55:6 invites people to seek the Lord while He may be found.
Isaiah 55:6: Seek ye the LORD while he may be found, call ye upon him while he is near:
Contradiction with Jeremiah 29:13
Amos 8:12 predicts a fruitless search for God's words, yet Jeremiah 29:13 assures that those who seek God with all their heart will find Him.
Jeremiah 29:13: And ye shall seek me, and find [me], when ye shall search for me with all your heart.