Acts 15:8 And God, which knoweth the hearts, bare them witness, giving them the Holy Ghost, even as he did unto us; 9 And put no difference between us and them, purifying their hearts by faith.
1 John 2:27 But the anointing which ye have received of him abideth in you, and ye need not that any man teach you: but as the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you, ye shall abide in him.
We are to even check those who would purport to teach.
Acts 17:11 These were more noble than those in Thessalonica, in that they received the word with all readiness of mind, and searched the scriptures daily, whether those things were so.
The admonition has always been that it's the individual. The Catholic Church lies when it usurps the responsibility of the individual
John was writing about the specific question of accepting Jesus as the Christ, the Son of God. If it were about the immediate teaching of the individual about all truth then there would be no need for John himself to give instruction. All John is saying is that they should hold to the truth of who Jesus is as they have received it and not to be persuaded by those who would deny it.
Acts 17:11 praised the Jews in Thessalonica for studying scripture. But notice that what they are studying is if what they have been instructed by Paul was in accord with scripture. Catholics too have studies the Scriptures to see if what they have been taught by the Church is so and have come the the conclusion that yes, it is so. And one of those things that the Scriptures point to is the ability of the Church to teach with the authority of the Holy Spirit.
If all Christians have been anointed with the Holy Spirit to infallibly interpret Scripture, why does this not apply to the half of the world's Christians who are Catholic?