Practically everything was in common except that the Twelve now understood that the Messiah and the Lamb of God were one and the same person. Otherwise, the message was the same, repent so that God will send Jesus back and give Israel her kingdom (i.e. times of refreshing) - Acts 3.
No, here is what John was preaching about the Lord Jesus' appearance:
"Beloved, now are we the sons of God, and it doth not yet appear what we shall be: but we know that, when he shall appear, we shall be like him; for we shall see him as he is" (1 Jn.3:2).
Those who received John's epistles were taught that they might well be alive when the Lord appears--
"when he shall appear...we shall see him as he is."
They were also taught that
"when he shall appear... we shall be like him."
This will happen when the Lord descends from heaven and the living saints will put on glorious bodies just like the body of the Lord Jesus. The events of which are spoken of at 1 John 3:2 by John can only be in regard to the rapture spoken of here by Paul:
"Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed, In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed" (1 Cor.15:51-52).
This will happen when the Lord descends from heaven and the living saints will put on glorious bodies just like the body of the Lord Jesus.
According to Paul Sadler, the past President of the Berean Bible Society, only the members of the Body of Christ will be raptured:
"The 'secret' resurrection that will take place at the Rapture should never be confused with the 'first' resurrection at the Second Coming of Christ. Those who rightly divide the Word of truth now see that only the members of the Body of Christ will be raised at the Rapture" [emphasis mine] (Sadler, Exploring the Unsearchable Riches of Christ [Stephens Point, WI: Worzalla Publishing Co., 1993], 167).
One thing's they for sure! They were NOT preaching...
Romans 4: 4 Now to him who works, the wages are not counted as grace but as debt. 5 But to him who does not work but believes on Him who justifies the ungodly, his faith is accounted for righteousness, 6 just as David also describes the blessedness of the man to whom God imputes righteousness apart from works
David lived under the law and he was saved by grace through faith, just like all of the others who were saved while living under the law:
"Therefore it is of faith, that it might be by grace; to the end the promise might be sure to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham; who is the father of us all" (Ro.4:16).