Translation:

45. That He may reward those who believe and work righteous deeds out of His Bounty: for He loves not those who reject Faith.

Notes (Tafseer)

3561. Though the repose and bliss will have been won by the righteous by their own efforts, it must not be supposed that their own merits were equal to the reward they will earn. What they will get will be due to the infinite Grace and Bounty of Allah.

3562. In form this clause is (here as elsewhere) negative, but it has a positive meaning: Allah loves those who have faith and trust in Him, and will, out of His Grace and Bounty, reward them in abundant measure.