Also, Christianity is not nor ever has been a static entity, and one can even see adjustments of various types in Acts and the epistles. Jesus even mentioned as such whereas he said that the Church would be guided until the end of time, thus implying that there will be changes.
To me an ' adjustment ' is Not a change of belief. It's Not interjecting something non-biblical with the biblical.
We 'adjust in understanding' about Scripture and Not change or add to Scripture.
For example: we now know more than Daniel knew at Daniel 12:4; Daniel 12:9.
A comprehensive concordance today allows us to search or research the Bible by topic or subject arrangement.
Thus, by taking one topic or one subject at a time we have a clearer picture of 1st-century Christianity.
So, just at Proverbs 4:18 lets us know spiritual light (Scripture) would grow brighter with the passing of time.
So, as we advance closer to Jesus' millennium-long perfect day of governing over Earth scriptural understanding also grows. Even now Jesus is guiding the Christian congregation until the ' end of time ' meaning the end the time of wickedness on Earth because the wicked will be destroyed forever as per Psalms 92:7. Those ruining the Earth will be brought to ruin as per Revelation 11:18 B.
Who ' remains ' are the figurative humble meek/ sheep to inherit the Earth - Psalms 37:9-11; Proverbs 2:21-22.
We are nearing Jesus' glory time of Matthew 25:31-33,37,40 when Jesus will separate the figurative 'sheep' before the executional words from Jesus' mouth rids the Earth of the 'goats' - Revelation 19:14-16; Isaiah 11:3-4.
Then, mankind will see the return of the Genesis ' Tree of Life ' on Earth for the ' healing of earth's nations ' according to Revelation 22:2. That is why we are all invited to pray the invitation of Rev. 22:20 for Jesus to come !
Not come and bring the end of time, but the end of time for wickedness on Earth.
As far as Acts yes there were adjustments because the temporary Constitution of the Mosiac law ended and people needed to adjust to Not keeping that temporary law for ancient Israel.
There is a warning found at Acts of the Apostles 20:29-30 to beware that false clergy would come.