it depends on the prophet in particular
if he'd want u to preach, you'd be his prophet, unfortunately, Prophet Muhammad (PBUH) was the last prophets and there are no more prophets after him..
They are needed to preach the Gospel to us.
to preach, and teach about the gospel of our lord and savior jesus christ.
All prophets warned man against sin.
Biblically speaking, the word "preach" first appears in Nehemiah 6:7, referring to the prophets. It is from the Hebrew qara, which means "to call, call out, cry out, proclaim." In the New Testament, "preach" is from the Greek kerusso, "to be a herald, to proclaim."
All the prophets spoke mainly against the sin and idol worship done by man.
The statement "How can he preach unless he be sent?" suggests that someone cannot effectively spread a message or teach without being authorized or given permission. It highlights the importance of being officially commissioned or endorsed in order to have credibility and authority in preaching or teaching.
yes
In order to fulfill the will of God. Moses spoke to the Israelites, and taught them the Torah, as per God's will. See also:More about MosesThe Israelite prophets
Christians were told to preach to the Gentiles and Jews because they were falling away from the Lord's teaching. There were several times throughout the Bible where the Lord instructed the Prophets to teach the non-Christians to help save them and change their ways.
when he was at age 40 Prophets don't claim to be prophets. They are assigned the duty of Prophet-hood by Almighty God and then they proclaim that they had been assigned to preach to people that their Creator is Only ONE Almighty God Who deserves worship.
not entirely sure if he was an "abolitionist", but he did preach against slavery (and alcohol)