God’s plan for the church under the new testament is different in several respects from those living under the old testament, for example God’s plan for the church in ministry is different under the new testament than it was under the new testament. God deals with the church differently than he did with the Israelites who were not born again.
First of all, the old testament prophet was the only ministry in operation from the standpoint of preaching or teaching the people by inspired utterance. That’s not true under the new testament, under the new testament God has set the five fold ministry in the church for the perfecting of the saints (Eph. 4:11-12).
Not only that, but under the new testament every Christian believer is to follow the holy spirit for himself, under the old covenant there was a sacrificial system for worship because God was dealing with spiritual dead people, they couldn’t worship God in spirit and in truth.
But under the new covenant, believers are not to set up some kind of a system for believers to worship God or to communicate with Him. Believers are to worship God in spirit and in truth and they are to be led by their spirit.
Under the old testament, the only people who were specially anointed by God were the prophet, priest and king. The king was anointed by the Holy Spirit to stand in that office but he was not anointed to preach. The priest was anointed by the Holy Spirit to stand in that office but he wasn’t a preacher either, he taught the law to the people so they would obey God’s commandments and precepts but he wasn’t a preacher.
Of course, the priest had a ministry under the old testament but it was not necessarily a ministry of preaching and teaching, they did exhort the people about the ways of the Lord and about carrying out the sacrificial system but actually under the old testament the prophets were the only preachers or ministers the people had. The prophet was the only one who could speak for God, as he was inspired by the Holy Spirit.
However under the new testament, God hasn’t put prophets in that office to lead or guide believers. Every believer has the Holy Spirit in him to lead and guide him, each believer can hear from God for himself. Therefore, under the new testament it is unscriptural to seek guidance through a prophet.
You see, under the new testament we have a better covenant based on better promises (Heb 8:6) and we don’t need to seek direction for our lives from anyone but God and because believers are born again, they can be led by the Holy Spirit in their own spirit (Rom. 8:14).