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.
One of the most important aspects of our salvation is understanding fully what God has done in us through Christs’ sacrifice for us. Our enemy works at deceiving us in these areas so that he can take advantage of our lives. We need to understand the redemptive work that God has already fulfilled in us when we were born again. One of those key areas is the work of justification.
Justification means to be declared righteous, and therefore approved by God. This gift of righteousness is what gives us the right to all that we have available to us as a child of God. The devil works at trying to convince you that you are not right with God. If he succeeds, he will hinder your faith in receiving what you have a right to. God demonstrated His righteousness (right standing with Him) through justification, which we have received through faith in Christ Jesus. You don’t work to get right with God, once you are born again you are right with God.
For example, when someone is born into a family and they are placed within their families will, their inheritance belongs to them because they are part of the family. Once we became born again, being given by God His righteousness, we not only became a part of the family, but we were provided an inheritance. It’s ours by birthright. We did not earn it, we were given this right because we are God’s children. Don’t fall for the devils lie that you don’t have a right to your inheritance. It’s yours because you have already been made right with God.