Can you explain the conflict between 2 Corinthians 5:10 and Isaiah 43:25? 2 Corinthians 5:10(KJV)


  10 For we must all appear before the judgment seat of Christ; that every one may receive the things done in his body, according to that he hath done, whether it be good or bad.


Isaiah 43:25(KJV)


  25 I, even I, am he that blotteth out thy transgressions for mine own sake, and will not remember thy sins.


These scriptures appear to contradict each other. Can you explain, please?
There is no contradiction when we understand the nature of the "judgment seat" of Christ.  That seat is in contrast to the "great white throne".


  For we [believers] must all appear before the judgment seat of Christ; that every one may receive the things done in his body, according to that he hath done, whether it be good or bad.


At 2 Cor. 5:10, the word for judgment seat is bema.  This is believers only.  We know this because the context for this is in verse 5. 


  Now he that hath wrought us for the selfsame thing is God, who also hath given unto us the earnest of the Spirit.
  2 Cor. 5:5


Only believers have the deposit of the Spirit unto eternal life.  We will appear before Christ at the bema.  It is not for judgment as sins are forgiven, but for rewards.

"At this bema believers are to be made manifest, that each may "receive the things done in (or through) the body," according to what he has done, "whether it be good or bad." There they will receive rewards for their faithfulness to the Lord."
Vines

That seat is identical to the one Isaiah 43:25 refers.  It is not for condemnation as transgressions are blotted out and sins are forgiven, but for reward.  Of course there may not be reward, but one still is saved as though through fire (1 Cor. 3:15).

At the great white throne in contrast, there is judgment of the dead, not the living in Christ.  Again the living in Christ appear at the bema.  All others, the dead, appear at the thronos (the throne of God) for judgment.


  And I saw a great white throne, and him that sat on it, from whose face the earth and the heaven fled away; and there was found no place for them.  And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works.
  Rev. 20:11-12


So, there is no conflict between 2 Corinthians 5:10 and Isaiah 43:25.