No, we learn from their mistakes as well as the things they got right. One thing I loved about scripture, even before becoming a Christian, is it never whitewashed events or left out the things people did wrong.
Peter also preached salvation by grace through faith, it just took him a little longer to realise.
Acts 11:16-17 (on recounting his experience with Cornelius)
16 Then I remembered the word of the Lord, how He said, ‘John indeed baptized with water, but you shall be baptized with the Holy Spirit.’ 17 If therefore God gave them the same gift as He gave us when we believed on the Lord Jesus Christ, who was I that I could withstand God?”
Acts 15:7-11 (on the dispute that arose over keeping the Law for the Gentiles)
7 And when there had been much dispute, Peter rose up and said to them: “Men and brethren, you know that a good while ago God chose among us, that by my mouth the Gentiles should hear the word of the gospel and believe. 8 So God, who knows the heart, acknowledged them by giving them the Holy Spirit, just as He did to us, 9 and made no distinction between us and them, purifying their hearts by faith. 10 Now therefore, why do you test God by putting a yoke on the neck of the disciples which neither our fathers nor we were able to bear? 11 But we believe that through the grace of the Lord Jesus Christ we shall be saved in the same manner as they.”