True. But if those “instructions” go beyond repenting and believing the Gospel(that is that Jesus Christ’s death on the cross atoned for our sins) we are in danger of preaching a different Gospel as the Galatians were warned by the Apostle Paul.
New Testament = Instructions in my statement.
No more no less.
i guess Peter was preaching another gospel when he gave “instructions” in Acts 2:38.
for that matter St Augustine must have been following another gospel as well.