What had Jesus not yet said by Acts chapter 3?
By Acts chapter 3, Jesus had not yet said anything about shutting down the temple, ending the law, or announcing that they were no longer under law and were now under a new manifestation of God's grace. He had not yet spoken those things, so Peter and the Eleven could not be expected to believe them.
Les explains that you cannot assume what God is going to say; you must wait until He has spoken it and then believe it. He points to Deuteronomy 29:29, where the secret things belong to the Lord but the revealed things are for us, and to Romans 10:17, where faith comes by hearing and hearing by the Word of God. The Word of God is not a vague mishmash; it is what God has actually spoken, as the Old Testament prophets like Ezekiel declared, 'The Word of the Lord came to me.' During His earthly ministry, Jesus made things clear when the disciples were supposed to believe them. But in Acts chapter 3, Jesus had not yet said a word about shutting down the temple, about no longer being under law, or about a new manifestation of God's grace. Therefore, He did not expect Peter and the Eleven to believe what He had not said. They were not negligent; they simply did not know.