Determination means that one has to continue with patience and perseverance. I'm not getting the desired result. "Oh what is this Krsna consciousness, I give up." No. Determination. It is a fact. Because Krsna is saying this it must happen. There is nice example. That a girl is married to a husband. She's hankering after a child. So if she thinks that "Now I am married, I must have immediately a child." Is it possible? Just have patience. You just become faithful wife, serve your husband, and let your love grown up and because you are husband and wife, it is sure you'll have children. But don't be impatient. Similarly, when you are in Krsna consciousness, your perfection is guaranteed. But but you'll have patience, determination. That "I must execute. I should not be impatient." That impatience is due to loss of determination. And how that loss determination is there? Due to excessive sex life. These are all consequences.

(From Srila Prabhupada's talk on Bhagavad-gita 6.16-24 — February 17, 1969, Los Angeles)