(I'm re-posting this for someone today.)
Unasked-for advice is usually received as criticism.
Imagine I come to you and say, "Did you know there are some really nice clothes on sale at Macy's today?"
The thought comes to you: "He doesn't like my clothes."
This "friendly advice" is a form of criticism and judgmentalism.
Mostly (but not entirely), people give unasked-for advice in an attempt to change people. If you want to advise someone because you see they are having a problem and you've got the answer, try asking their permission: "May I suggest something?" Or, I may ask you "What is a good restaurant to eat at?" Then, you give me your thoughts on this.
That's cool. But a lot of advice-giving is about control and manipulation. It produces anger and bitterness. Who likes controlling people who are out to change them?
On changing other people: you cannot do it. Period. You can force people to do something. You can threaten them, imprison them, and guilt-manipulate them. But the human heart, the human spirit, cannot be changed by other people.
The human heart is influenced by other people. That's different. In my life there are a handful of people who have significantly influenced me. One now comes to mind. In the 1980s he was in my church in East Lansing. I was privileged to be in a small group with him and his wife that met weekly. He was a great scholar, which I admired. He spoke when asked, and never advised when not asked. I found this intriguing because he was a psychologist, and psychologists (so I thought) were there to give advice. His character and demeanor and humility and Christ-in-him were compelling. So much so that, eventually, I sought him out to advise me about some things. Which he did, with wisdom and love.
Instead of advising others whether they ask for it or not, focus on connecting with Jesus, and allow Jesus to work on the stuff inside of you that he knows about and is able to change.
I need to be continually saved from my own self. You, "the other," cannot do this. You are not my Savior. But if you remain connected to Jesus and allow him to change your heart about things, the chances increase that God will use you to effect real heart-change in me.
The life goal is to know Christ, not advise others. God can use the brokenness effected in you to bring breakthrough to the people around you.