This question was raised on CDF, but the participant who raised the issue refused to abide by the rules of CDF and had to be removed. That's neither here nor there now though. Let us examine the matter objectively.
Challenger: Peter explicitly states: "For never have I eaten anything profane and unclean." (Acts 10:14) Therefore, Peter never did.
Moderator: Please document anywhere AFTER Acts 10 where Scripture records that St. Peter continued to observe the OT Jewish dietary laws.
There we hit our impasse - the challenger merely asserts I am wrong to say St. Peter ever partook of "unclean foods." It must be noted, I did not make that assertion! I simply required the challenger to submit valid documentation, from Scripture, which states St. Peter continued to observe the OT Jewish dietary laws AFTER Acts 10. The responsibility to document or retract remained with the challenger, not with the moderator.
Now, if we objectively look at the context, let's recap what happens in Acts 10:
- St. Peter goes up on the rooftop to pray, and is brought into a trance (v. 10).
- Peter receives a vision of a large sheet containing all the four-legged creatures of the Earth, plus reptiles and birds of the sky (v. 11-12)
- St. Peter is told to "kill and eat." (v. 13)
- St. Peter responds that he cannot, for he has "never eaten anything profane or unclean." (v. 14)
- The voice speaks to him: ""What God has made clean, you are not to call profane." (v. 15)
- This happens three times and then the sheet is drawn back into Heaven.
- Three servants of the God-fearing Gentile, Cornelius, come to St. Peter and say: "Cornelius, a centurion, an upright and God-fearing man, respected by the whole Jewish nation, was directed by a holy angel to summon you to his house and to hear what you have to say."
- OT Jewish law forbade Jews from even visiting Gentile households (implied in Acts 11:3), much less eat their food, but what does St. Peter do? He immediately goes with them to Cornelius' house!
- St. Peter not only visits the household of the Gentile Cornelius, but he eats with him!
- In Acts 11 the "circumcised believers" confront St. Peter and challenge him precisely over the visit and the eating amongst Gentiles. (11:2-3)
- St. Peter explains the vision he received and why he went to Cornelius' household and ate with them (v. 4-18).
- The "circumcised believers" then accepted what St. Peter said and rejoiced that God had sent His redemption to the Gentiles too! (v. 18).
If we're going to rationalize at all here - then logic demands that we come to the conclusion that St. Peter AFTER Acts 10 no longer observed the Old Testament Jewish dietary laws. To conclude he remained in compliance with the OT laws after this point is illogical/irrational for he would actually now be in violation of what God told him through the messenger/angel. Is the proof absolute? Well, based on Acts 11:3, it's pretty close to absolute - the logical conclusion is that since he was dining with Gentiles in their household that no matter what was served, it would be "unclean" unless these Gentiles had gone through the ritual cleansing process of the Jews - which is even more unlikely. His action also brought the criticism of the "circumcised believers" indicating that they felt he had violated their customs. Again, for him NOT to partake in these foods would also mean that St. Peter directly violated the command from God which came to him through the vision of Acts 10 and clarified through the "messenger" (angel) of the Lord.