Here is both faith and assurance. "O that I had them," is the language of many a doubting heart, while both this very faith and assurance are in possession. This assurance is essential to faith; without it faith has no existence. Consider the nature of this faith and assurance: "We believe, and are sure." Of what? That their names were written in heaven; that they were the elect of God? No: but says Peter to our Lord, "We believe and are sure, that thou art Christ the Son of the living God, and that thou hast the words of eternal life." Their minds were as sure of this truth as of their existence; so must ours be at all times, and in all circumstances.
"But is this faith and assurance I. Then, blessed he God, I am a partaker of both: I do believe, I am sure that Christ is the Son of God, and that he, and he alone has the words of eternal life; but I want to he sure of my own interest in the Son of God." Bless the Spirit for revealing Christ in the word, and revealing him in thine heart according to the word. Go on with thy present blessed faith and assurance. It will make Christ precious to thy soul: it will cause thy soul to cleave to him: thou wilt say, "None but Christ." In due time the Spirit will fully manifest thy interest in his love and salvation.
Consider the blessedness of this faith and assurance: it was for want of this that "many disciples went back and walked no more with Christ." John 6:66. It is believing and being sure that Christ is the Son of God, and that he has the words of eternal life, that causes any poor sinner to follow him, to cleave to him, to call upon him, to hope in him, and to expect all salvation from him. Little as some may think of this faith, low as some may rate this assurance, yet our Lord honors it: he pronounces Peter blessed for it. Peter does not say, I believe and am sure that I am a child of God, and that my sins are forgiven; but, "Thou art Christ, the Son of the living God." What says our Lord to this? "Blessed art thou: for flesh and blood hath not revealed this unto thee, but my Father which is in heaven." Matthew 16:17.
Rejoice, O believing soul! thou hast a revelation from God thy heavenly Father, even whilst thou art doubting. All thy salvation depends on this truth; all thy comfort results from belief and assurance of it. The more steadily and confidently you believe and hold this truth in your conscience, the more solid peace, holy comfort, and heavenly joy.