John Gill emphasizes the importance of a clear conscience in the life of believers, explaining that a heart that does not condemn us allows for confidence before God. He clarifies that this does not imply a state of sinless perfection but rather a heart cleansed by the blood of Christ, which fosters boldness in approaching God. Gill highlights that true brotherly love is essential, as those who harbor hatred cannot stand confidently before God. The assurance of our relationship with God is rooted in our love for one another, which confirms our regeneration and adoption as His children. Ultimately, this love enables believers to approach God with freedom and confidence, knowing He hears and answers their prayers.

Ver. 21. Beloved, if our heart condemn us not,.... Which must be understood, not of a stupidity of mind, as is in unregenerate men, who have no sense of sin, no sorrow for it, or remorse of conscience on account of it; or as is in them who are past feeling; having their consciences seared as with a red hot iron; such cannot be entitled to the advantages that follow; nor is it of persons the apostle speaks, but of himself, and Christians, the beloved of the Lord, and one another, who had an experience of the grace of God upon their souls, and made a profession of religion: nor does it design such a purity of heart and life in believers, as that their hearts do not smite, reproach, and condemn them for sin at any time, for such a state of perfection is not to be attained to and expected in this life; but rather a conscience purged by the blood of Christ, or an heart sprinkled from an evil conscience by that blood, which speaks peace and pardon, so that there is no more conscience of sin, for the removal of which that is applied; and this gives boldness and confidence at the throne of grace: though it is best of all to confine it to the case of brotherly love; for the sense is not, if our heart condemn us not of anything but of the want of brotherly love, or insincerity in it, [then] have we confidence towards God; or with him, at the throne of his grace: such can draw nigh to him, and stand before him with an holy and humble confidence, when such as hate the brethren, as Cain did, in whom the apostle instances, and those that go in his way, cannot; whose heart condemned him, his conscience smote him, and he went from the presence of the Lord; but those that love the brethren have confidence of their relation to God; by this they know their regeneration, and by that their adoption, and so that they are the children of God; and can therefore draw nigh to God as their Father, and call him so; they can come with an holy boldness and intrepidity of mind before him, and use a parrhsia, "freedom of speech", with him; can tell him all their mind, pour out their souls unto him, and lay before him their case and wants; they have confidence of his power, faithfulness, and willingness to supply their need, and fulfil all his promises to them, and that their prayers will be heard, answered, and regarded by him in his own time.