Paul knew God was a just God and knew of His rewards therefore said of Alexander a coppersmith which did him much evil, may the Lord reward him according to his works.(2 Timothy 4:14,15). There are many rewards spoken of in scripture and depending on if we do righteousness or wickedness all choices will be rewarded. (Isaiah 3:10-11). Say ye to the righteous, that it shall be well with him: for they shall eat the fruit of their doings. Woe unto the wicked! it shall be ill with him: for the reward of his hands shall be given him.
Different times does the word tell us that in the final days the Lord will arrive and bring His reward according to the work of us all good or bad! (Revelation 22:11-14) He that is unjust, let him be unjust still: and he which is filthy, let him be filthy still: and he that is righteous, let him be righteous still: and he that is holy, let him be holy still. And, behold, I come quickly; and my reward is with me, to give every man according as his work shall be. I am Alpha and Omega, the beginning and the end, the first and the last. Blessed are they that do his commandments, that they may have right to the tree of life, and may enter in through the gates into the city…… (2 Corinthians 5:10)…. (Isaiah 62:11-12).
We learn in Psalms that the fear of the Lord and His judgments are true and righteous, and as His servant if we heed His words it is a warning for us to live and do what is right and by keeping His ways brings great reward. (Psalm 19:7-11). The law of the Lord is perfect, converting the soul: the testimony of the Lord is sure, making wise the simple. The statutes of the Lord are right, rejoicing the heart: the commandment of the Lord is pure, enlightening the eyes. The fear of the Lord is clean, enduring for ever: the judgments of the Lord are true and righteous altogether. More to be desired are they than gold, yea, than much fine gold: sweeter also than honey and the honeycomb. Moreover by them is thy servant warned: and in keeping of them there is great reward.