The apostles possessed more empirical supports for their faith than we can ever hope to possess, and certainly their spiritual “report cards” did not suffer for the fact.
Jesus’ Yoke and Burden

It appears that the original context for Jesus’ “Comfort for the Heavy-Laden” saying has been lost; however, passages in the apocrypha indicate that Jesus was speaking of Torah study and the rigors of first-century discipleship.
New Testament Canon

While God had used individual writers to record the books themselves, the actual acceptance of those books as being from God was subject to a long transition, a process of testing.