John and Peter
wrote their epistles during the time when the present dispensation was in force and received by Christians living in the present dispensation. So common sense dictates that the doctrine found in those epistles is for the present dispensation. We can see exactly what gospel Peter was preaching and it is not the gospel of the kingdom:
"Who his own self bare our sins in his own body on the tree, that we, being dead to sins, should live unto righteousness: by whose stripes ye were healed...Forasmuch as ye know that ye were not redeemed with corruptible things, as silver and gold, from your vain conversation received by tradition from your fathers; But with the precious blood of Christ, as of a lamb without blemish and without spot" (1 Pet.2:24, 1:18-19).
Do you really believe that Peter was preaching the gospel of the kingdom there? If you do then it is certain you know nothing about Paul's gospel which He referred to as "the preaching of the Cross."
Do you never even check for yourself to see if what you are being taught is correct? Evidently not!