Can you lose your salvation? What happens to a person in salvation?

Jude 3

3 Beloved, although I was very eager to write to you about our common salvation, I found it necessary to write appealing to you to contend for the faith that was once for all delivered to the saints.

(ESV)

Eternity past to eternity future

1. Union with Christ
   1. Ephesians 1:3-14; 2:4-7

Eternity past

1. Chosen, elect
   1. Ephesians 1:4
2. Predestined
   1. Ephesians 1:5
3. Book of life
   1. Revelation 13:7b-8

The Cross

1. Ransomed
   1. Revelation 5:9
2. Redemption
   1. Ephesians 1:7
3. Propitiation
   1. Romans 3:25

Conversion

1. Gospel
   1. Romans 1:16
2. Regeneration (born again)
   1. John 3:3
   2. Titus 3:5
   3. 1 Peter 1:3-5
   4. Ephesians 2:1-9
3. Repentance
   1. Acts 2:38
4. Belief (faith)
   1. Acts 13:48; 16:31
5. Forgiveness
   1. Ephesians 1:7
6. Justification
   1. Romans 3:21-26
   2. (Titus 3:7)
7. Sanctified
   1. 1 Corinthians 1:2; 6:11
8. Sealed with the Holy Spirit
   1. Ephesians 1:13
   2. 2 Corinthians 5:5
9. New creation
   1. 2 Corinthians 5:17
   2. Ephesians 2:10
10. Adoption
    1. Ephesians 1:5
11. Eternal life
    1. Romans 6:23
    2. John 10:27-30
12. Freed from power of sin
    1. Romans 6:22

Immediately following conversion until Death (or Jesus’ return)

1. Sanctification
   1. Hebrews 10:14
2. Perseverance (Preservation)
   1. Revelation 14:12 (and the seven letters)
   2. Jude 24-25

Eternity future

1. Eternal salvation
   1. Hebrews 5:9-10
2. Sabbath rest
   1. Hebrews 4:9-10
3. Salvation as inheritance
   1. Hebrews 1:14
   2. Colossians 3:23-24

How is a person changed in salvation?

Out of the above list, which events involve a fundamental change in a person who is saved? Are these changes reversible? Undoable?