We may not feel guilty, but the Scriptures speak of our guilt before God as an objective reality (Romans 3.19,20).
Some people have less sensitive consciences than others, but how we feel does not change how God sees us.
Guilt is an objective reality and justification, which deals with it, is also objective. It is something God does; it is a declaration God makes about us. It is, as the 17th-century Shorter Catechism of the Church of Scotland says, ‘an act of God’s free grace, in which he, the Judge of all the earth, acquits the guilty sinner, and declares him to be righteous, and accepts him as righteous in his sight’.