nostr:npub128t3e2maxutmyxl3rfh9xn07qa34htqcmfff0ynz5qz945khky3qm7axqq nostr:npub1qfkcklnmes45z75y7y8dkud5yll8vp5eq5ysk9rmgqdxeasv8unsrfj6kq nostr:npub1sweetvyurzytyvqthtk45x5hk4kvvat8t7r35ruc6tgc9ak8av9qrwwjk4 nostr:npub1nf9vm6uhs4j7yaysmjn9eqlf7et5t6hvrkdqgpd995vcc9yfjyas0pxa3x nostr:npub1k8u5csaulf800zljf7tey95l6e42v38lxljcsu60rdpd7te3jpyqfgznyl 
The apostles were able to teach their doctrine out of the Old Testament, therefore it goes as follows
Old Testament -> church -> New Testament
As opposed to:
church -> Old and New Testament

You need to presuppose sacramentalism, there's nothing to imply they taught anything beyond OT doctrines with the clarification that Jesus is the Christ (Messiah) and that forgiveness is only found in Him, with baptism replacing circumcision, and the Lord's Supper replacing Passover.
At the council at Jerusalem, when debating over the necessity of circumcision and the law of Moses, they concluded that apart from abstaining from fornication, from meat offered to idols and from blood, there is no necessary burden to the Gentiles. If you needed the sacraments to be saved this'd be the time to ratify them.