Hence how could he say he has ascended into heaven at the start of his ministry?
Venus,
Once you understand that there are three "YOUs" Just as there are three that make up the ONE GOD, it makes perfect sense.
And the very God of peace sanctify you wholly; and I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ. - 1 Thess. 5: 23
So, acording to scripture, you are constructed as three parts - that as a "whole" AND individually can be accurately referred to as "YOU". The Watchtower denies the biblical tri-partite nature of man and adopts a materialist definition. This is where many theological problems with the Watchtower originate.
And no man hath ascended up to heaven, but he that came down from heaven, even the Son of man which is in heaven. - John 3: 13
Clearly, Jesus was in two places at the same time. Paul also tells of a man who went to the third heaven.... another case of someone being in two places at the same time.