Romans 11:33-36

v33-36: All things, especially those to do with our salvation, is from God, He is "the source and fountain" and through Him, "through Christ, the God-man." If it is from Him and through Him, "everything should be to him and for him."  They are for His purposes and to His glory.  Our salvation is God's idea and His work and reveals His glory and it is to Him we give our praise.

Romans 12:1-2

v1-2: In view of the mercies of God, our response is to surrender ourselves to God.  The "presenting of the body to God implies not only the avoiding of the sins that are committed with or against the body, but also the use of the body... in the service of God."  It is the Word of God which tells us how to live this life of surrender to God.