When Jesus was a child he was perfect without sin, but he wasn't King. The angels were joyful because they knew that Jesus was the answer to mankinds problems. John also knew that Jesus was the solution, he did not want to baptize him at first. But it was done as commanded. To fulfill scripture. Jesus did not become anointed until after he was baptized with water.
I feel that those called by Jehovah or Jesus are of the 144,000. Jesus said that many are invited, but only few are chosen. Also he made mention in his story that those who are not dressed in proper wedding attire will be cast out into the darkness. So if you were not truly called by Jehovah or Jesus you are not of this fold. So you can partake of these emblems, but that does not mean you are truly invited.
To the brothers outright telling people they are not anointed, they are going to answer to God for that. For the brothers out there who sincerely respect peoples decisions to partake and not judge, I got nothing but love for you.
I feel that those called to this fold are literally called by Jehovah or Jesus. I also believe the calling they recieve is their token of what's to come. They can truly say within their hearts that they are of the 144000. The Apostles were sanctified in Heaven by Jesus, he charged them to cast out spirits and perform healing by means of Jehovahs spirit. To my understanding no prophet before them was able to do the things they were doing. So Jesus had already arranged for them to be with him in Heaven.