Acts 2 is not Ephesians 2:8-9 KJV! Peter told those folks to DO something for the remission of sins (Acts 2:38 KJV) looking forward that their sins may be blotted out (Acts 3:19-21 KJV) while Paul preached to believe something to be saved and that of course by the gospel by which we are saved 1 Corinthians 15:1-4 KJV).
You need to get over wanting to interpret things (as you're horrible at it made evident even by your above post) and believe what saith the scripture. When did the prophets prophesy that grace should come unto Israel (another clue to you that this is different than Paul's preaching!)
1 Peter 1:7 That the trial of your faith, being much more precious than of gold that perisheth, though it be tried with fire, might be found unto praise and honour and glory at the appearing of Jesus Christ:
1 Peter 1:8 Whom having not seen, ye love; in whom, though now ye see him not, yet believing, ye rejoice with joy unspeakable and full of glory:
1 Peter 1:9 Receiving the end of your faith, even the salvation of your souls.
1 Peter 1:10 Of which salvation the prophets have enquired and searched diligently, who prophesied of the grace that should come unto you:
1 Peter 1:11 Searching what, or what manner of time the Spirit of Christ which was in them did signify, when it testified beforehand the sufferings of Christ, and the glory that should follow.
This is just silly. since when was the atoning sacrifice of Christ for Israel or anyone for that matter (you know the 'lamb of God') "something we do?"
The goodness of God leads us to repentance--taught by both Peter and Paul.
You give me a headache with your fracturing the Bible 24x7. Who would be interested except someone who writes IRS regulations?