Every prayer, every sermon, every waking moment, every dream, all of life must be saturated with Christ. Here’s C.H. Spurgeon’s thoughts on preaching and living the Christ-centred life:
See to it then, beloved, that you never pray a prayer which is not sweetened with Christ. I would never preach a sermon — the Lord forgive me if I do — which is not full to overflowing with my Master… for a sermon without Christ in it [is] a Christless sermon! A brook without water; a cloud without rain; a well which mocks the traveler; a tree twice dead, plucked up by the root; a sky without a sun; a night without a star. It were a realm of death — a place of mourning for angels and laughter for devils. O Christian, we must have Christ! Do see to it that every day when you wake you give a fresh savor of Christ upon you by contemplating his person. Live all the day, trying as much as lieth in you, to season your hearts with him, and then at night, lie down with him upon your tongue. It is said of Samuel Rutherford, that he often did fall asleep talking about Christ, and was often heard in his dreams, saying sweet things about his Saviour. There is nothing which can preserve us and keep us from sin, and make our works holy and pure, like this “bundle of myrrh.” [from C.H. Spurgeon “A bundle of Myrrh” sermon a on Song of Songs 1;13]
For help on living the Christ centred life see my study notes on C.J. Mahaney’s excellent book, the Christ-Centered life.