(HH Kadamba Kanana Swami, 10 August 2012, Ljubljana, SB 1.8.21)
The example of Putana gives us great hope that, although we perform devotional service imperfectly, we may receive the mercy of Krsna anyway, because He tends to overlook the faults and accept the good. That is Krsna. See, see how kind is Krsna!
Srila Prabhupada explains that when it comes to going back to Godhead, we are not so sure if we want to go. But Krsna is eager, very eager to bring us back to Godhead. In fact, His desire for us to go back to Godhead is stronger than our own desire.
Yes, Krsna will surely take that devotee back who engages in devotional service spontaneously, without asking for anything in return.