_3dly_, It ought to be performed with great diligence, inasmuch as it is no easy matter to arrive to such a knowledge of ourselves, and the secret working of our hearts and affections, in what respects things divine and heavenly, or to discern the truth of grace, so as not to mistake that for a saving work, which has only the external shew of godliness, without the power of it; this requires great diligence and industry to know: Accordingly the Psalmist, in speaking concerning the performance of this duty, says, _I commune with mine own heart, and my spirit made diligent search_, Psal. lxxvii. 6. The thing to be enquired into is not barely, whether we are sinners in general, or exposed to many miseries in this life, as the consequence thereof? for this is sufficiently evident by daily experience. But we are to endeavour after a more particular knowledge of ourselves, and accordingly are to enquire; whether sin hath dominion over us to such a degree, so that all the powers and faculties of our souls are enslaved thereby, and we commit sin in such a way, as denominates us, as our Saviour expresses it, _servants of sin_? John viii. 34. or, whether sin be loathed and abhorred, avoided and repented of? and as to our state, we are to enquire; whether we have ground to conclude that we are justified, and thereby delivered from the guilt of sin, and the condemning sentence of the law? or, whether we remain in a state of condemnation, and the wrath of God abideth on us? We must enquire, whether the work of grace be really begun, so that we are effectually called, and enabled to put forth spiritual actions from a renewed nature? and whether this work is going forward or declining? what is the strength or weakness of our faith? Also we are to enquire, what is the general tenor of our actions? whether the ends we design in all religious duties are right and warrantable? whether our improvement in grace bears any proportion to the means we are favoured with? Moreover, we are to examine ourselves; whether we perform all those relative duties that are incumbent on us, so as to glorify God in our conversation with men, whereby we endeavour to do good to, and receive good from them, and accordingly improve our talents to the glory of God, from whom we received them? These and such like things are to be enquired into, which will be more immediately subservient to the attaining this privilege of assurance.