Just as a different perspective (a long time after your original post...but never mind) we've had Shirley Carpenter teaching us over the last few weeks and she's been speaking of the difference between the grace we are given freely and the grace we "grow" in, just as Jesus did. We are to grow in favor, like Jesus did (Paul wrote of growing in grace, and it being multiplied). If you choose to cultivate relationship with God so that you spend more time with Him and be diligent in seeking Him, you WILL grow in favor with God. Not only that, we will grow to love Him more closely and we also will encounter His love in a more rich way. Looking at it from that perspective, I think it's reasonable to conclude that the more time spent on God, the more we seek Him for more of Him, the more love we have access to...because of where WE are positionally. "Your love is our reward, that's why we ask for more of YOU."

There are other definitions of "reward" I think you should consider. For example, the root meaning is "to take notice of", but it also means: blessing, honor, advantage, and in terms of specific definitions, psychology defines reward as "any pleasant event that follows a response and therefore increases the likelihood of the response recurring in the future", a satisfying return or profit, or to satisfy or gratify. If Jesus' love satisfies you, you have been rewarded. If you see it as a blessing or an honor or an advantage, then you are seeing it as a reward. The concept of reward you're talking about is common, but it is extremely narrow.
My recent post convicted in the wilderness?