"And in the Acts of the Apostles, Christ gives the keys of the kingdom to Peter!"
How does Peter unlock the Kingdom in the book of Acts?
By preaching the Gospel!
Those who hear, repent and believe in Jesus are let in. Peter is still letting people into the Kingdom via the Scriptures to this very day. Those who faithfully preach the Gospel are his true heirs and hold those keys also.
"And in the Acts of the Apostles, Christ gives the keys of the kingdom to Peter!"
Please give the scriptural referance in the book of Acts where Christ gives the keys to the kingdom to Peter. In case you are having a hard time finding it, try looking in Matt 16. But don't stop there. Go on to Matt 18 and see where Jesus gives the same authority to the rest of the apostles.