I have been to different churches and some of the pastor preach about fasting to overcome sins and some of the pastor or preaches said you can overcome sin by fasting

my question is can someone overcome sin by fasting

If you've not given your life to Jesus then there is no way you can overcome sin. The proper method to walk in a Christ-like life is first being saved, then sanctified, and then living a holy life by studying and living according to biblical standards

DannyG8:
I have been to different churches and some of the pastor preach about fasting to overcome sins and some of the pastor or preaches said you can overcome sin by fasting

my question is can someone overcome sin by fasting

I am afraid what you have encountered there are false teachers and prophets that Jesus Christ warned you against. They deceive people with lies which have no basis in the teachings of Jesus Christ, and so are against God.

What is sin? Sin is simply disobedience of the commandments of God, in this case, the commandments of God are the teachings of Jesus Christ, the Truth of God. And we know that according to Jesus Christ, the only way to free oneself from the clutches from sin is to choose submit to and obey His teachings/commandments which are given to you by God Himself.

John 8 vs 31-36
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31. So Jesus said to the Jews who believed in him, “If you continue to accept and obey my teaching, you are really my followers.
32. You will know the truth, and the truth will make you free.”
33. They answered, “We are Abraham’s descendants. And we have never been slaves. So why do you say that we will be free?”
34. Jesus said, “The truth is, everyone who sins is a slave—a slave to sin.
35. A slave does not stay with a family forever. But a son belongs to the family forever.
36. So if the Son makes you free, you are really free.

By learning the Truth of God, the teachings of Jesus Christ, one learns what sins is. And through continued acceptance(trust) and obedience of the teachings/commandments, one is set free from sin and becomes a disciple/follower of Jesus Christ instead.

No amount of fasting and prayer can deliver anyone from sin... submitting to the Truth of Jesus Christ is the only way!