The soul of a man is a battle ground ,comprising of the good and bad part of him always struggling to take dominance , that which he feeds more will prevail.
For the redeemed of the Lord our spirit is renewed, and set apart for God, but our bodies remains the same.
So what struggle are we talking of in actual sense, it's about the will of a man and the will of the Father. The will of a man is directly opposite the will of the God. The flesh does not want anything spiritual , so it tends to fight by making a man disobedient to his maker.
For the fact that the spirit of a believer is renewed does not mean that everything around him changes spontaneously. His mind has to first be renewed by the word , so that he will position himself in line with God's plan, in so doing releases power that is in his regenerated spirit. But the body doesn't want such stress, it constantly wants leisure and comfortability, forgetting that there is a way that seemeth right unto a man but the end thereof is destruction. So what are the ways out of this ordeal. It's simple!
Know that you are not alone : Jesus said I will not leave nor forsake you. This alone is an assurance that you can conquer any mountain set be for you. The reason why some Christian struggle with serving God is because they are doing it on their own without revelation of how God want us to fellowship with him.
And always remember that the Greater one lives inside of you.Subdue your flesh: There is a constant battle between the flesh and the spirit. The flesh wants pleasure at any cost, it promises nothing but death. But the spirit gives life. Always subdue your flesh by surrendering to the authority of the HOLY GHOST (The best friend to have, MIGHTY AND LOVING). Hallelujah!
Submit to the word: Most believer know Jesus as their Saviour and not as Lord. It is in surrendering to the Lordship of Jesus that victory over foes comes. Psalm:119.11
I have hidden your word in my heart that I might not sin against you.
For we know we wrestle not against flesh and blood. So with this consciousness we have to live our lives from a spiritual point of view. A wise man said 'Life is spiritual , so I have to live my life from a spiritual point of view'.
You can do all things through Christ which strengthens you!