A new era for our priestly ministry of intercession as Christians began the day Jesus died on the cross. That is when God Himself reached down and tore the veil that hid the Holiest of Holies in the temple in Jerusalem. That veil was a very tall, very thick curtain made of animal skins and fabric sewn together by hand. It had lasted for hundreds of years. It was so strong, only God could have ripped it open from top to bottom. (Mere humans would have had to start from the bottom).
Until then, only the High Priest could enter that room which contained the ark and was the dwelling place of God, and he could only enter once a year to intercede for the people. Aaron, and the priests who followed him, entered with incense to represent the prayers of the people, but only after the priest had been ceremonially cleansed and purified for this role.
There were some instances of people praying on behalf of others before that time. Notably, (in Genesis 18) when Abraham interceded for his nephew, Lot and his family, when the Lord, in the form of an angel, came to tell Abraham that He planned to destroy Sodom and Gomorrah. (In response to Abraham's intercession the angels did get Lot and his two daughters out alive).
The ordinary Israelite left praying to the priests. In other religions too, people pay their priest or shaman exhorbant fees to pray to their gods on their behalf.
Now you and I, since that veil was torn open, if we have trusted Christ to wash away all our sins, can come into God's presence and intercede, or pray for others. We can take up our priestly ministry of intercession.
We don't have to go through rituals or ceremonies before we pray, but the effectiveness of our prayers depends on our own spiritual relationship with Christ. Have we confessed all our own sins? Have we appropriated God's forgiveness by faith? Do we really believe that God will hear and answer our prayers for others? Remember, we will only receive answers to the degree that we believe God.
Our daily life can soil our lives and get between us and our holy God, so it is good to search our hearts before we pray for others, to see whether we have some sin to confess, so that we have clean hands and feet - spiritually speaking.
When we pray - for ourselves or others - our spirit is in fact, at the throne of God in Heaven. Therefore, this is holy, heavenly work, and not to be taken lightly.
We have an example to follow, for Hebrews 4:14 declares that Jesus is our great High Priest, who ever lives to make intercession for us. He understands our frailities. Jesus is a human like us. Since our praying is done in Christ, by His name, we can learn more about our role, by looking to Jesus.
Intercession is not some trivial pursuit. (Though I confess that doing it privately for many years, makes it seem like a rather secretive thing. To brag on our work of intercession somehow makes it disappear).
Let us be grateful then, that we may enter into God's presence to intercede for others every day and many times a day. We need to review sometimes just what prayer is, search our hearts, to confess sins that have crept in, and to worship God heartily, so as to strengthen our faith in Him.
Our priestly ministry of intercession is truly a high and holy calling. If you are a sincere Believer and child of God, I challenge you to take it up as one of - or, perhaps as your main ministry. There is a great need for faithful and committed intercessors!