Test or Relationship?
I think the reason Jesus mentions reward in the gospels - that our reward will be great in Heaven and that we will receive much more than what we give up - is not to motivate us towards a distant goal, so much as to give us a reflection about what that says about Him.
It's to show that He is good. "I want to give you things, not merely take things away" is the jist of it. And as a motivating force the future is generally weak. It's hard to save for a new car, let alone the next life! But we can have Him today in relationship even if the reward spoken of in the gospels may be distant. (I make a purposely false dichotomy here since Christ is our reward.)
I think it's impossibile to be a Christian and focus on the reward, even though in the temporal realm it's true we can be good savers by focusing on our retirement. Why? Because being a Christian is infinitely more difficult than saving for retirement. If our 401K asks for 10% of our income, God asks for everything, our very selves. That is impossible except by focusing on Christ's goodness, which he demonstrated in word and deed. This is the antidote against falling into the easy trap of seeing life as a seemingly pointless test in which God is neutral, as an impartial judge would be.
One of the greatest gifts we can ask of Jesus is the gift of final perservance, but that still focuses on self and "the test". How much more moving and motivating to pray with today's antiphon!: "You are the men who have stood by me faithfully in my trials..." (Lk 22:28) which we could also read as: "You are the men who have stood by me faithfully in your trials." In other words, seeing God as good even in the midst of woe.