Romans 3:21-26 English Standard Version (ESV)
The Righteousness of God Through Faith
21 But now the righteousness of God has been manifested apart from the law, although the Law and the Prophets bear witness to it— 22 the righteousness of God through faith in Jesus Christ for all who believe. For there is no distinction: 23 for all have sinned and fall short of the glory of God, 24 and are justified by his grace as a gift, through the redemption that is in Christ Jesus, 25 whom God put forward as a propitiation by his blood, to be received by faith. This was to show God’s righteousness, because in his divine forbearance he had passed over former sins. 26 It was to show his righteousness at the present time, so that he might be just and the justifier of the one who has faith in Jesus.
The Greek word here for manifest is paneroo meaning to become known, to be plainly recognized, thoroughly understood. This in reference to the person of Jesus Christ in His earthly ministry. He was not recognized by everyone as the Son of God. That being said, then how is it the definition contains the description “thoroughly understood”? Because sight had to be mixed with faith in order to know the truth.
Another way of thinking about His manifestation is that God the Father sent the Son to show us how righteousness performs. Here in Romans 3 Jesus has already ascended to the throne of God yet in verse 26 Paul declares that His righteousness is shown at that present time.
John 16:7-10 English Standard Version (ESV)
7 Nevertheless, I tell you the truth: it is to your advantage that I go away, for if I do not go away, the Helper will not come to you. But if I go, I will send him to you. 8 And when he comes, he will convict the world concerning sin and righteousness and judgment: 9 concerning sin, because they do not believe in me; 10 concerning righteousness, because I go to the Father, and you will see me no longer;
Seeing His righteousness is now presented to us by the Holy Spirit.