From
The Didache, chapter 6.
1 See that no one make thee to err from this path of doctrine, since he who doeth so teacheth thee apart from God.
2 If thou art able to bear the whole yoke of the Lord, thou wilt be perfect; but if thou art not able, what thou art able, that do.
3 But concerning meat, bear that which thou art able to do. But keep with care from things sacrificed to idols, for it is the worship of the infernal deities.