1. SUCH is the voice of every true believer in Christ, so long as he abides in faith and love. _He that followeth me_, saith our Lord, _walketh not in darkness_: And while he hath the light, he rejoiceth therein. _As_ he _hath received the Lord Jesus Christ, so_ he _walketh in him_. And while he walketh in him, the exhortation of the apostle takes place in his soul day by day, _Rejoice in the Lord always, and again I say, rejoice_. 2. But that we may not build our house upon the sand, (lest when the rains descend, and the winds blow, and the floods arise and beat upon it, it fall, and great be the fall thereof) I intend, in the following discourse, to shew, what is the nature and ground of a Christian’s joy. We know, in general, It is that happy peace, that calm satisfaction of spirit, which arises from such a testimony of his conscience, as is here described by the apostle. But in order to understand this the more throughly, it will be requisite to weigh all his words: whence will easily appear, both what we are to understand by _conscience_, and what, by the _testimony_ thereof; and also, how he that hath this testimony rejoiceth evermore. 3. And, first, what are we to understand by _conscience_? What is the meaning of this word that is in every one’s mouth? One would imagine, it was an exceeding difficult thing, to discover this, when we consider, how large and numerous volumes have been from time to time wrote on this subject: and how all the treasures of ancient and modern learning have been ransack’d, in order to explain it. And yet it is to be fear’d, it has not received much light from all those elaborate enquiries. Rather, have not most of those writers puzzled the cause; _darkening counsel by words without knowledge_; perplexing a subject, plain in itself, and easy to be understood? For set aside but hard words, and every man of an honest heart will soon understand the thing. 4. God has made us thinking beings, capable of perceiving what is present, and of reflecting or looking back on what is past. In particular, we are capable of perceiving, whatsoever passes in our own hearts or lives; of knowing whatsoever we feel or do; and that either while it passes, or when it is past. This we mean when we say, man is a _conscious_ being: he hath a _consciousness_ or inward perception both of things present and past relating to himself, of his own tempers and outward behaviour. But what we usually term _conscience_, implies, somewhat more than this. It is not barely, the knowledge of our present, or the remembrance of our preceding life. To remember, to bear witness either of past or present things, is only one, and the least office of conscience. Its main business is to excuse or accuse, to approve ♦or disapprove, to acquit or condemn.