The criticisms of the early church are not much different from the criticisms of latter day critics.
" So then you believers in Jesus can just go on sinning and sinning because the grace of God has you forgiven ? "
They had the very same complaint in the first century, to which Paul anticipates, and addresses -
"What then shall we say? Should we [we Christians] continue in sin that grace may abound? " (Rom 6:1)
What follows is a matter of removing ignorance and hindrences to revelation. You have to SEE something of the truth.
God is faithful. But you exercise faith and the FAITHFUL God will follow through.
Do not be ignorant. See the reality.
You have been crucified with Christ and buried with Him and raised with Him.
You can walk in newness of life because of utter identification with Christ.
" Absolutely not! We who have died to sin, how shall we still live in it?
Or are you ignorant that all of us who have been baptized into Christ Jesus have been baptized into His death. We have been buried therefore with Him through baptism into His death, in order that just as Christ was raised from the dead through the glory of the Father, so also we might walk in newness of life. (vs.2-4)"
This is the Christian moral of being utterly identified with Christ.
His life becomes our history.
God is faithful to cause this to happen.
God is faithful to cause this to be the believer's experience.
But you must abide in the realm of the indwelling Holy Spirit.