<p>1:3 <i>To whom, after his suffering, he also showed by many convincing proofs- </i>Acts 1:3 says that the Lord showed Himself to be alive to the disciples &quot;by many infallible proofs&quot;. The suggestion is that they simply didn't accept Him as He stood there before Him; they failed to grasp that He was for real. They gave Him food to eat to check Him out; and He again ate before them in Galilee on His initiative.</p><p><i>That he was alive, being seen by them for forty days, and speaking about the kingdom of God- </i>The Greek is literally: 'Speaking about the things concerning the Kingdom of God'. And this is exactly how the content of the Apostolic preaching is described in Acts 8:12; 19:8; 28:31. Clearly what the Lord taught them became the basis of their teaching to others. They were a continuation of Him on earth, just as our witness should be likewise. It could even be that &quot;the things concerning the Kingdom of God&quot; became a technical term for a body of material which the Apostles taught, having heard it directly from the Lord during those 40 days.</p>