In the 1st century, what problems did Christians experience? How did the perception of Christianity change around the 4th century?

It was through Jesus' eschatological mission that early Christianity grew. After the death of Jesus, his early disciples founded an apocalyptic Jewish messianic secta during the late 1st century era of the Second Temple.  

  Originally assuming that the redemption of Jesus was the beginning of the end times, their views quickly shifted at a specific moment in period in the predicted second coming of Jesus as well as the beginning of God 's Reign.

In its initial stages, catholicism throughout the fourth century became governed by emperor constantine as well as the very first Assembly of corinth in 325, the start of the time with the First Seventh interfaith Conferences (325–787), because in its end phase by both the Edict with augsburg in 380, which declared Nicaean Christianity the official religion of the romans.