In the second volume of Manton’s collected works is a section “called Twenty Sermons” published together. William Bates, in an introduction to the volume writes,

The main design of them is to represent the inseparable connection between Christian duties and privileges, wherein the essence of our religion consists. The gospel is not a naked, unconditionate offer of pardon and eternal life in favour of sinners, but upon most convenient terms, for the glory of God and the good of men, and enforced by the strongest obligations upon them to receive humbly and thankfully those benefits. The promises are attended with commands to repent, believe, and persevere in the uniform practice of obedience. The Son of God came into the world, not to make God less holy, but to make us holy, that we might please and enjoy him; not to vacate our duty, and free us from the law as the rule of obedience, for that is both impossible and would be most infamous and reproachful to our Saviour. To challenge such an exemption in point of right, is to make ourselves gods; to usurp it in point of fact is to make ourselves devils. But his end was to enable and induce us to return to God, as our rightful Lord and proper felicity, from whom we rebelliously and miserably fell by our disobedience, in seeking for happiness out of him. Accordingly the gospel is called ‘the law of faith,’ as it commands those duties upon the motives of eternal hopes and fears, and as it will justify or condemn men with respect to their obedience or disobedience, which is the proper character of a law. These things are managed in the following sermons in that convincing, persuasive manner as makes them very necessary for these times, when some that aspired to an extraordinary height in religion, and esteemed themselves the favourites of heaven, yet woefully neglected the duties of the lower hemisphere, as righteousness, truth, and honesty; and when carnal Christians are so numerous, that despise serious godliness as solemn hypocrisy, and live in an open violation of Christ’s precepts, yet presume to be saved by him. Though no age has been more enlightened with the knowledge of holy truths, yet none was ever more averse from obeying them.

Thomas Manton, The Complete Works of Thomas Manton, vol. 2 (London: James Nisbet & Co., 1871), 175–176. In short, the gospel was given to make us fit for God, and the sermons were given to encourage that end. The first two sermons on the text Psalm 32:1-2

SERMON I

Blessed is he whose transgression is forgiven, whose sin is covered. Blessed is the man unto whom the Lord imputeth not iniquity, and in whose spirit there is no guile.’—Ps. 32:1, 2.

Manton begins the sermon with the note that we all seek happiness — of which we were deprived by sin; for happiness is only from God. Therefore, we must be reconciled to God to become truly happy:

The title of this psalm is ‘A psalm of instruction,’ and so called because David was willing to show them the way to happiness from his own experience. Surely no lesson is so needful to be learned as this. We all would be happy: the good and bad, that do so seldom agree in anything, yet agree in this, a desire to be happy. Now, happy we cannot be but in God, who is the only, immutable, eternal, and all-sufficient good, which satisfies and fills up all the capacities and desires of our souls. And we are debarred from access to him by sin, which hath made a breach and separation between him and us, and till that be taken away there can be no converse, and sin can only be taken away by God’s pardon upon Christ’s satisfaction. God’s pardon is clearly asserted in my text, but Christ’s satisfaction and righteousness must be supplied out of other scriptures, as that 2 Cor. 5:19, ‘God was in Christ reconciling the world to himself, not imputing their trespasses to them.’ Where the apostle clearly shows that not imputing transgressions is the effect of God’s grace in Christ. 

 Thomas Manton, The Complete Works of Thomas Manton, vol. 2 (London: James Nisbet & Co., 1871), 177. Thus, opens a theme was quite consistent throughout the Puritans: holiness and happiness are inextricably intertwined. Happiness was a common and consistent theme in their writing — which is interesting because they are uniformly portrayed as dour. Yet, there are thousands of reference to happiness in Manton: 264 uses of the word “happy” in volume 2 of works alone. There are more than 1,000 references to happy in Thomas Brooks collected works; over 500 in George Swinocks collected works; more than 1,000 references in Richard Sibbes’ works; et cetera.