Romans 12 "... in view of God's mercies.. "  Paul begins.. because God has chosen us and shown mercy to us, that we might belong to Him by faith in Jesus Christ... we are to live as His people. And this begins with us offering ourselves as "a sacrifice, living and set apart for God."   Paul calls this "logical Temple worship" ( CJB) or " your spiritual service of worship" ( NASB).

A living sacrifice.  As Jesus laid down His life for us.. we are called to lay down our lives, take up our crosses and follow Him.  This is true worship.  It is a blessed union with our Lord, possible only because of His choice to show us mercy.  We are "acceptable" and "holy" sacrifices, because Jesus has made us so!  We can only please God by fully surrendering to Him, fully worshiping Him.. as living sacrifices.

The rest of this chapter spells out for us what this looks like -

First of all, we won't look like the rest of the world - we won't think like them, nor will we fit into their boxes.  We will be "transformed" - metamorphosis will take place as our minds are renewed by the Holy Spirit and the Word.  This is how we will begin to know what God wants for us.  This is how we know what is "good and acceptable and perfect".

A transformed mind will allow us to have a proper or "sober estimate" of ourselves.  We will recognize that we are part of the "one body" - made up of Jews and Gentiles alike; the body of Christ consists of all who are grafted into the Root.  We are all "in this together".. if we trust in Jesus.

We who are transformed by our Lord are given gifts to serve one another.  We are called to use our individual gifts to the fullest extent of our faith.  These are gifts of grace, given for the whole body of Christ, the church.
Prophets should prophecy by faith.
Servants should serve by faith.
Teachers should teach by faith.
Counselors should counsel - comforting and encouraging others.. by faith.
Givers should give... generously by faith.
Leader should lead with diligence... by faith.
Those who do acts of mercy should do them with "cheerfulness.".. and faith .

As fully surrendered, holy, living sacrifices, transformed by God's Word and Spirit we will exhibit His character:
Our love will be real.. not hypocritical.
We will hate evil and cling to what is good.
We will be devoted to each other, showing brotherly love and respect.
We will work hard in our service to our Lord.
We will "rejoice in hope, be patient in [our] troubles, and continue steadfastly in prayer." 
We will share with others, practicing hospitality.
And finally, we will forgive those who mistreat us, help those who are in need, keep peace between us whenever we can, and allow God to take care of any "vengeance. " 

This way of living doesn't come naturally.  It is the opposite of "being conformed to the world".
It is a tranformation brought about by God when we offer ourselves to Him fully.

Father in heaven... may Your will be done in us according to these Truths. We need to be transformed by Your Word and Spirit. Take our bodies, they are living sacrifices, given to You in worship today. In view or Your mercies, through Christ Jesus our Lord, for it is in His name we pray. amen