The doctrine in Hymns - "A Mighty Fortress is our God" (verse 2)

Verse 2, #1: Did we in our own strength confide, our striving would be losing;

Sinners cannot save themselves by good works and deeds. We are born with a fallen sinful nature and are unable to meet the perfect standard of righteousness that God requires for justification. Therefore, anyone relying on being declared righteous on the basis of their own strength and effort will be unsuccessful. The only way to salvation is through Jesus Christ and the cross by faith.

Galatians 2:16 yet we know that a person is not justified by works of the law but through faith in Jesus Christ, so we also have believed in Christ Jesus, in order to be justified by faith in Christ and not by works of the law, because by works of the law no one will be justified.

Verse 2, #2: Were not the right Man on our side, the Man of God’s own choosing:

The nation of Israel is promised a redeemer is throughout the Old Testament. This redeemer was foretold to be God’s chosen one the savior and Messiah of the world.

Isaiah 54:5 For your Maker is your husband, the Lord of hosts is his name; and the Holy One of Israel is your Redeemer, the God of the whole earth he is called.John 17:25 O righteous Father, even though the world does not know you, I know you, and these know that you have sent me.

Verse 2, #3: Dost ask who that may be? Christ Jesus, it is He;

Paul went about proclaiming to the Jews that the Messiah spoken about in the Old Testament was in fact Jesus Christ. Still to this day many if not most of the Jewish people do not accept the fact Jesus is the Messiah and the savior of the world.

Acts 17:3 explaining and proving that it was necessary for the Christ to suffer and to rise from the dead, and saying, “This Jesus, whom I proclaim to you, is the Christ.”

Verse 2, #4: Lord Sabbath, His Name, from age to age the same,And He must win the battle.

Jesus Christ the eternal son of God is unchanging and his days will never end. The battle has already been decided as Satan is doomed to be thrown into lake of fire for all eternity. Jesus Christ and his church will prevail as Scripture makes clear.

Matthew 12:8 For the Son of Man is lord of the Sabbath.”
John 1:1-2 In the beginning was the Word, and the Word was with God, and the Word was God. (2) He was in the beginning with God.
Matthew 16:18 And I tell you, you are Peter, and on this rock I will build my church, and the gates of hell shall not prevail against it.