“acts of righteousness.” This is the figure of speech, Metonymy (Cp. Bullinger; Figures of Speech Used in the Bible). The result, righteousness, is put instead of the action that produces it. A more literal rendition of the verse, without the figure, would read, “Take care that you do not do your acts of righteousness before men, to be seen by them….”
“you have.” The Greek is in the present tense, “you have,” and it is making the point that God is storing up rewards now, and will dispense them later.
“no reward laid up with your Father.” This is a very strong warning for people to watch the motives that drive their actions. If a person does good deeds, which normally would be rewarded by God in the future Paradise, but he only does them to impress people, when people are impressed that is his payment. God will not pay us for work we do not do for His glory. Instead of “from your Father,” the more natural meaning of the Greek preposition para, translated “with” in the REV, is “beside,” but that is not as clear as “with” is to the average reader. If we have the translation as “with,” or even more literally, “beside,” combined with the present tense of “having” a reward, then the translation is: “you have no reward laid up beside your Father.” The picture being painted by this verse is very biblical and very oriental: God is in heaven sitting on His throne, and he is watching what people are doing on earth and making up rewards and setting them beside Him so that He can give them out in the future. The biblical picture is that God makes the rewards as the people do the good deeds, He does not manufacture them in the future and distribute them at that time. Of course we learn from other verses, such as 2 John 1:8, that if we are not faithful, we can lose the rewards we have stored up for ourselves.