Reprobation means that those left to ones own desires and folly, falling further and further into increasing sin with the chance of repentance. The only problem being that they like the Elect, before the Elect know God, are "Dead in Trespasses and sins" alienated in their minds to God. The Reprobate are given the general graces of the witness of God in Creation and their conscious so that they are without excuse and that God is just (Romans 1).
Also God says to Moses: "I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion." (Exodus 33:19, Romans 9:15). And God is just dealing with the "Dead in Trespasses in sins" having mercy and compassion upon whomever He chooses. For He has chosen to lavish His love (1 John 3:1), mercy and compassion upon the elect and is just to do so for those undeserving it.
For none of us deserved it.
We do not know who the Elect truly are, nor the Reprobate save for evidence of faith or not. Therefore we are to preach the Gospel of Christ to all nations, peoples, tribes and tongues. Those we think never would come to Christ sometimes do (think Saul of Tarsus and Roe of Roe V Wade). Some will repent while unable to speak on their deathbeds.
IMHO: Many do not want to consider the word "predestined" when it occurs 6 times in the New Testament, nor the word "elect" when it occurs 25 times. To those who have problems with Predestination and Election, I ask what do those Biblical words mean in your church or to you?
If folks have no answer, I refer them to the best teacher of all Scripture - The Holy Spirit who teaches us all things of regarding Christ, Righteousness and Truth.
Thomas Aquinas ??