"manner". There is the key word. Not "form", nor "substance".
Manner: A way of doing something or the way in which a thing is done or happens. (American Heritage Dictionary)
Then this:
Hebrews 9: 19 For when Moses had spoken every precept to all the people according to the law, he took the blood of calves and of goats, with water, and scarlet wool, and hyssop, and sprinkled both the book, and all the people,
20Saying, This is the blood of the testament which God hath enjoined unto you.
21Moreover he sprinkled with blood both the tabernacle, and all the vessels of the ministry.
22And almost all things are by the law purged with blood; and without shedding of blood is no remission.
23It was therefore necessary that the patterns of things in the heavens should be purified with these; but the heavenly things themselves with better sacrifices than these.
24For Christ is not entered into the holy places made with hands, which are the figures of the true; but into heaven itself, now to appear in the presence of God for us:
25Nor yet that he should offer himself often, as the high priest entereth into the holy place every year with blood of others;
26For then must he often have suffered since the foundation of the world: but now once in the end of the world hath he appeared to put away sin by the sacrifice of himself.
27And as it is appointed unto men once to die, but after this the judgment:
28So Christ was once offered to bear the sins of many; and unto them that look for him shall he appear the second time without sin unto salvation.
How did Christ enter the into the Holy place in Heaven?
In spirit form or in human form? The Priest must came and poured the blood out on the mercy, Christ went into the Holiest place of purifying mankind once and forever. So too will he return for those of us who look for His return, but not just us but for all who believe on Him unto salvation.
So was He at that time in Spirit form or human form, did He represent God or did He represent man? If He represented man then would He not have been in human form to represent the humanity He became and died for?