This is exactly the goal for which you came into this world, to choose the good. In order that there be freedom of choice, it’s necessary for there also to be a power opposing holiness. On the contrary, each time that a difficulty or obstacle arises in learning, praying, faith or any other Mitzvah, we have to strengthen ourselves exceedingly and tell ourselves, that this is a sign that Hashem does indeed love our Mitzvos very much and He also believes in us – He is therefore sending us this difficulty in order that we have proper free will, and when we do overcome it, we will give Him satisfaction.
An analogy which we can use to understand this concept can be of a soldier, who after performing a heroic act, is recognized by superiors to be a valiant soldier, and he is sent on a even more dangerous mission deep in enemy territory. The soldier becomes angry and says, what do they want from me, I’ve already proven my abilities, why do I deserve such a punishment? His commanders answer him with a warm smile; you don’t understand at all your role in the army. This isn’t a punishment at all, and this isn’t the place to show your heroism. You have to understand that there is a real war going on with enemy forces which need to be annihilated. Therefore, when you first joined the army we started off slowly, and when we saw your successes, we decided to send just you.
Hashem loves us very much, and believes in our abilities, that we are capable. He therefore sends us on battles and missions, sometimes even more difficult ones that the previous ones.