At any point of a man's life, there seems to be a challenge, trouble or habit which he seeks to overcome .
These challenges or habits may seem difficult to break free or let go from but this is only because we try to do these things with our own strength rather than with the grace of God.
1john,4:4
[4]Little children, you are of God [you belong to Him] and have [already] defeated and overcome them [the agents of the antichrist], because He Who lives in you is greater (mightier) than he who is in the world.
This bible passage tells us that we have already defeated our demons because we have the spirit of God living in us.
1john,5:4
[4]For whatever is born of God is victorious over the world; and this is the victory that conquers the world, even our faith.
1 Corinthians 15
[57]But thanks be to God, Who gives us the victory [making us conquerors] through our Lord Jesus Christ.
These passages speak of God granting us victory over any challenges we might face but one thing is prerequisite.
The last verse says victory through our Lord Jesus Christ. So for us have this victory, we must not only accept Jesus as our Lord and Savior but also obey his commandments, the most important of all being Love.
So when next you're confronted with problems or life throws challenges at you, remember, you've already won that battle. You just have to have faith in him through which we are saved (Jesus Christ).