Behold, all things have become new!

"Therefore, if anyone is in Christ,
  he is a new creation;
  old things have passed away;
  behold, all things have become new!"
2 Corinthians 5:17


(Matthew Henry, 1662-1714)

Christians are new creations-they have a new heart and new nature. So great is the change which the grace of God makes in the soul, that old things are passed away: old thoughts, old principles, and old practices-are passed away; and all these things must become new. Regenerating grace creates a new world in the soul-all things are new. The renewed man acts . . .
  from new principles,
  by new rules,
  with new ends,
  and in new company.


(Adam Clarke, 1762-1832)

If anyone is in Christ, he is a new creation; old things have passed away. It is vain for a man to profess affinity to Christ, while he is unchanged in his heart and life, and dead in trespasses and sins. For he who is in Christ, that is, a genuine Christian, having Christ dwelling in his heart by faith-is a new creature; his old state is changed:
  he was a child of Satan-he is now a child of God;
  he was a slave of sin, and his works were death-he is now made free from sin, and has his fruit unto holiness, and the end everlasting life;
  he was before full of pride and selfishness-he is now meek and humble;
  he formerly had his portion in this life, and lived for this world alone-he now has God for his portion, and he looks not at the things which are seen but at the things which are eternal. Therefore, old things are passed away.


(Barton Johnson, 1833-1894)

Behold, all things have become new! The man is not only mended, but he is new made. Formerly, all was in chaotic disorder-now there is a new creation which God Himself owns as His workmanship, and which He can look on and pronounce very good. The conversion of a man from idolatry and wickedness is denominated a new creation. Born anew, we are new creatures who must live a new life. All things have become new:
  the affections,
  the motives,
  the thoughts,
  the hopes,
  the whole life!