The N. T. was not yet formed, but there was oral transmission.
Let's read Acts 15 again:
28 For it seemed good to the Holy Ghost, and to us, to lay upon you no greater burden than these necessary things;
29 That ye abstain from meats offered to idols, and from blood, and from things strangled, and from fornication: from which if ye keep yourselves, ye shall do well. Fare ye well.
See? No greater burden than these necessary things -- nothing else.
Let's read Acts 15 again:
28 For it seemed good to the Holy Ghost, and to us, to lay upon you no greater burden than these necessary things;
29 That ye abstain from meats offered to idols, and from blood, and from things strangled, and from fornication: from which if ye keep yourselves, ye shall do well. Fare ye well.
See? No greater burden than these necessary things -- nothing else.
If it is ONLY those things then stealing is permitted.
Or those were some basic things the holy spirit guided them to require for ppl to enter a congregation/place of worship. Then once they were there they would learn more;
Acts 15:19-21, " 19 Therefore my judgment is that we should not trouble those of the Gentiles who turn to God, 20 but should write to them to abstain from the things polluted by idols, and from sexual immorality, and from what has been strangled, and from blood. 21 For from ancient generations Moses has had in every city those who proclaim him, for he is read every Sabbath in the synagogues.”