If it the teaching of Jesus, why not in the gospel?
Early Christian?
Paul warn Christian church in Corinthian
1 for 6
8 Instead, you yourselves cheat and do wrong, and you do this to your brothers and sisters.
9. Or do you not know that wrongdoers will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor men who have sex with men[
a] 10 nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God. 11 And that is what some of you were. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God.
Even when Paul alive cheating happen
Verse 8