To be a Christian means to believe that Christ is Lord of all of life. There is no distinction between sacred and secular in the ultimate sense. All of life is lived before the face of God, under the Lordship of Christ.
(Abraham Kuyper)

     No one would ever dare to rise in a meeting and say, "I am a Christian" if he had not surrendered his whole being to God and had taken Jesus Christ as his Lord. It was only then that he could say, "I am saved!" Today, we let them say they are saved no matter how imperfect and incomplete the transaction, with the proviso that the deeper Christian life can be tacked on at some time in the future. Can it be that we really think that we do not owe Jesus Christ our obedience?
(A.W. Tozer)

     It is as unbiblical as it is unrealistic to divorce the Lordship from the Saviorhood of Jesus Christ. He is 'our Lord and Saviour Jesus Christ,' and saving faith is commitment to Him who is both Son of God and Saviour of men….The error which we might call only-believism [leaves sinners] supposing that all they have to do is to trust Christ as a sin-bearer, not realizing that they must also deny themselves and enthrone Him as their Lord.
(Dr. John Stott)