We know about the man whom Jesus healed who had been waiting for 38 years by the side of the pool hoping to get well. The question Jesus asked him was if he really wanted to be healed (Jn.5:6). There are different ways to interpret this incident and take lessons. Some can say that if he really wanted to be healed he would have done something more than just hoping to get healed. We really don't know what his limitations were and why he didn't do anything more. But the fact that the man stayed there so long even though things looked so hopeless is itself a sign of his desire to be healed. Ultimately that got him healed!
Many of life's situations are like this. Things seem to drag on and on and there is no hope in view. There are times when we need to do something more than what we have done so far, such as seeking help from others. We may need to change some of our ways: if what we have been doing hasn't helped, it's unrealistic to expect that it will in future. The main thing is to keep aiming for the resolution of the problem without giving up.
Take the example of an alcoholic who comes to the Lord in repentance. There are cases where the Lord miraculously takes away the desire from him and empowers him so that even the smell of drinks does not tempt him. But in the majority of cases there is battle involved in gaining mastery over alcohol.
It may be similar even in the matter of overcoming sin. If God gives us instant victory, praise Him! But in most cases there is a battle. God is interested not just in stopping the sin, but also in moulding our overall character. For example, He wants to show us how helpless we are without His strength, teach us how to become vigilant against temptations, and perhaps become able to teach others the way too. What is being tested in the meantime is our perseverance in seeking for victory. What can happen is that we give up along the way, 'accept' our limitations, lower our expectations from God, find justifications for our failures, find others to put the blame on, etc.
"You have need of endurance, so that when you have done the will of God, you may receive what was promised" (He.10:36). One of the things David prayed for after he had fallen in sin was a steadfast spirit (Ps.51:10). He used to be 'a man after God's own heart' till he fell, and he used to have a very intimate relationship with God, as we can see through his psalms. But he slowly backslid after he became king, and now he had fallen so badly. Now he realised that he ought to have been steadfast in his seeking after God without letting up (Ps.27:4).
No one who puts his trust in God and seeks Him will ultimately be put to shame (Is.49:23). Situations may not always work out for us because there are other people also involved, but God will always help us to come out on the top. He can strengthen us in our inner man so that we can rise up in our heart and mind over our situations. That's a big victory indeed.