Rom 12:1
Therefore, I urge you, brothers, in view of God's mercy, to offer your bodies as living sacrifices, holy and pleasing to God-- this is your spiritual act of worship.
What does it mean to offer our bodies as living sacrifices?

When God asks for sacrifices, He asks for only our best. He wants the first, not what’s left over.

Rom 12:2
Do not conform any longer to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God's will is-- his good, pleasing and perfect will.
It’s very clear that we as Christians are not to conform to the standards of acceptance of a morally decadent world.
How do we conform to the standards of this world?

To be transformed is to be “born again” with a new mindset, a new attitude.
We learn and understand what God’s will is for us by reading, studying, and meditating on His word and in prayer to Him, being submissive to the Holy Spirit.

Rom 13:10
Love does no harm to its neighbor. Therefore love is the fulfillment of the law.
If we obey the first two commandments, then all the others simply fall into place.

Rom 15:4
For everything that was written in the past was written to teach us, so that through endurance and the encouragement of the Scriptures we might have hope.
If we use the scriptures, both Old and New Testament to get the full picture we will be encouraged and strengthened. The more we read, the more we understand and the more we will trust in Him. It is only with the full context of scripture that we can understand.

Rom 15:13
May the God of hope fill you with all joy and peace as you trust in him, so that you may overflow with hope by the power of the Holy Spirit.
Imagine a clear glass. As we trust in Him, he begins to fill us (the glass) with joy and peace. He fills us more and more as we trust in Him more and more until finally our glass overflows. What might prevent us from allowing Him to fill us?

Rom 15:29
I know that when I come to you, I will come in the full measure of the blessing of Christ.
Paul has the Lord’s blessing for coming to them, the established church. This will be a time of spiritual nourishment and encouragement for Paul. God knows that Paul, like many true servants, needs refreshment from time to time.

Notice Paul did not do his own writing of this letter. Tertius wrote it. Is his eyesight failing so badly that he can no longer write?