To Stop Masturbation as a Christian, Take Every Thought Captive | 2 Corinthians 10:3-6

Masturbation is a sin that takes place between your ears, not between your legs. Sure, it involves a physical act, but the act is simply the consummation of a sin that starts in your mind. If you want to avoid masturbating and kick the habit for good, you must work on your mind. Victory over sexual sin starts with changing the way you handle your thoughts.
This is the truth that Paul communicates in his second letter to the church at Corinth. "Bring every thought into captivity to the obedience of Christ," says Paul. In other words, when a wicked thought enters your mind, when an evil desire stirs in your thoughts, take it captive. Make it your prisoner. Lock it in shackles so it can't do what it wants to do, which is lead you to sin.
This phrase, "bringing every thought into captivity," means to subdue, to ensnare, those thoughts that exalt themselves against the knowledge of God. And Paul doesn't say just some thoughts, or just a few thoughts, or even many thoughts, but "every thought." Every thought that enters your mind that has any chance of leading you to masturbate is a thought that you must bring into captivity by subduing it and ensnaring it. You must act quickly and decisively if you want to learn how to stop masturbation as a Christian.
One way to take every thought captive is to quote scripture whenever you think a wicked thought. As soon as you hear something, see something or read something that gets you thinking about masturbating, quote a verse from the Bible out loud. Here are a few versus you can consider using, tweaked to make them personal:
"Father in heaven, lead me not into temptation, but deliver me from the evil one" (Matthew 6:13)
"For I do not have a high priest who is unable to empathize with my weaknesses, but I have one who has been tempted in every way, just as I am--yet he did not sin" (Hebrews 4:15)
"I can do all things through Christ who strengthens me" (Philippians 4:13)
"I am blessed when I endure temptation; for when I have been approved, I will receive the crown of life which the Lord has promised to those who love Him" (James 1:12)
If you want to learn how to stop masturbation as a Christian, change the way you think. When you change the way you think, you change the way you act. When you change the way you handle wicked thoughts, you change the trajectory of your day--and your life.