The reason that I believe the words of Isaiah 61:1-2 must be words that refer to the Lord (Jesus Christ as Saviour), and not Isaiah, is because the phrases used all have parallels elsewhere in scripture that provide a clear explanation of their intended application.
Take first the expression 'The Spirit of the Lord GOD is upon me;' If we look back to Isaiah 42:1-4, it says ' Behold my servant, whom I uphold; mine elect, in whom my soul delighteth; I have put my spirit upon him: he shall bring forth judgement to the Gentiles.[2] He shall not cry, nor lift up, nor cause his voice to be heard in the street. [3] A bruised reed shall he not break, and the smoking flax shall he not quench: he shall bring forth judgment unto truth. [4] he shall not fail nor be discouraged, till he have set judgment in the earth: and the isles shall wait for his law.'
This should make you think seriously about applying Isaiah 61 to Isaiah. Verse 4 of Isaiah 42 makes it absolutely clear that only the Messiah is here intended. Only he can 'set judgment in the earth'. Only he can give law to the isles. So it's the same Messiah to whom the Spirit comes.
Look also at the expression 'mine elect, in whom my soul delighteth'. What did the Father say to Jesus at his baptism, 'This is my beloved Son, in whom I am well pleased.' [Matt:3:17]
Now look at the other expressions used. PLEASE READ CAREFULLY!
'to preach good tidings' - in Isaiah 52:7 it says,'How beautiful upon the mountains are the feet of him that bringeth good tidings, that publisheth peace; that bringeth good tidings of good, that publisheth salvation; that saith unto Zion, thy God reigneth!'
Is this not the Saviour?
'to bind up the brokenhearted' - It says in Psalm 147:3 'He [the Lord] healeth the broken in heart, and bindeth up their wounds'.
Is this not the same Lord?
'to proclaim liberty to the captives' - Isaiah 42:6,7. 'I the Lord have called thee in righteousness, and will hold thine hand, and will keep thee, and give thee for a covenant of the people, for a light of the Gentiles; [7] To open the blind eyes, to bring out the prisoners from the prison, and them that sit in darkness out of the prison house.'
'the opening of prison to them that are bound' - as above.
Are these both not references to the coming Messiah? Was Isaiah ever given 'for a covenant'?
'To proclaim the acceptable year of the LORD' - 'the year of acceptance'.Isaiah 49:8 'Thus saith the LORD, In an acceptable time have I heard thee, and in a day of salvation have I helped thee: and I will preserve thee, and give thee for a covenant of the people, to establish the earth, to cause to inherit the desolate heritages;'
Only the Messiah has the authority to claim 'in a day of salvation have I helped thee.'
Psalm 85:1,2: 'LORD, thou hast been favourable unto thy land: thou hast brought back the captivity of Jacob. [2] Thou hast forgiven the iniquity of thy people, thou hast covered all their sin. Selah.'