Able minister of the new testament
The phrase "able minister of the new testament" is a reference to Paul's self-description in 2 Corinthians 3:6, where he writes:
"But if the ministry of death, written and engraved on stones, was glorious, so that the children of Israel could not look steadily at the face of Moses because of the glory of his face, which was fading away, then how much more glorious will be the ministry of the Spirit!
For if the ministry of condemnation has glory, the ministry of righteousness exceeds much more in glory. For even what was made glorious had no glory in this respect, because of the glory that surpasses it. For if what was made glorious had been only glorious, it was not much more glorious; but we are speaking of the glory that surpasses.
For if that which fades away was glorious, what remains is much more glorious. So then, as there are those who say we speak in the name of men, we show that humanly speaking we are merely servants of Christ and stewards of the mysteries of God. Now it is God who said, 'Let light shine out of darkness'; it is the same God who made his light shine in our hearts to give us the light of the knowledge of God’s glory displayed in the face of Christ."
In this passage, Paul is contrasting the old covenant, which was written on stone tablets and was a ministry of death and condemnation, with the new covenant, which is a ministry of the Spirit and a ministry of righteousness. He is saying that the new covenant is far more glorious than the old, and that he and other ministers of the new covenant are merely servants of Christ and stewards of the mysteries of God.
The phrase "able minister of the new testament" is often used to describe someone who is qualified and empowered to preach and teach the gospel of Jesus Christ. It implies that the person has been entrusted with the responsibility of proclaiming the good news of salvation through faith in Jesus Christ, and that they have the ability and authority to do so.