THe following from the Sum of Saving Knowledge helped me greatly:

Hence he who hath closed bargain with God may strengthen his faith, by reasoning after this manner:

"Whosoever doth heartily receive the offer of free grace, made here to sinners, thirsting for righteousness and salvation: unto him, by an everlasting covenant, belongeth Christ, the true David, with all his sure and saving mercies: But I (may the weak believer say) do heartily receive the offer of free grace made here to sinners, thirsting for righteousness and salvation: Therefore unto me, by an everlasting covenant, belongeth Christ Jesus, with all his sure and saving mercies."

Hence may a weak believer strengthen his faith, by reasoning from this ground after this manner:

"He that, upon the loving request of God and Christ, made to him by the mouth of ministers, (having commission to that effect,) hath embraced the offer of perpetual reconciliation through Christ, and doth purpose, by God's grace, as a reconciled person, to strive against sin, and to serve God to his power constantly, may be as sure to have righteousness and eternal life given to him, for the obedience of Christ imputed to him, as it is sure that Christ was condemned and put to death for the sins of the redeemed imputed to him: But I (may the weak believer say) upon the loving request of God and Christ, made to me by the mouth of his ministers, have embraced the offer of perpetual reconciliation through Christ, and do purpose, by God's grace, as a reconciled person, to strive against sin, and to serve God to my power constantly: Therefore I may be as sure to have righteousness and eternal life given to me, for the obedience of Christ imputed to me, as it is sure that Christ was condemned and put to death for the sins of the re deemed imputed to him."

Hence may a weak believer strengthen himself, by reasoning from this ground after this manner:

"Whosoever, in the sense of his own sinfulness, and fear of God's wrath, at the command of God, is fled to Jesus Christ, the only remedy of sin and misery, and hath engaged his heart to the obedience of the law of love, his faith is not presumptuous or dead, but true and saving faith: But I, (may the weak believer say) in the sense of my own sinfulness, and fear of God's wrath, am fled to Jesus Christ, the only remedy of sin and misery, and have engaged my heart to the obedience of the law of love: Therefore my faith is not a presumptuous and dead faith, but true and saving faith."

Hence may the weak believer strengthen his faith, by reasoning from this ground after this manner:

"Whosoever believeth the doctrine delivered by the Son of God, and findeth himself partly drawn powerfully to believe in him, by the sight of life in him, and partly driven, by the fear of God's wrath, to adhere unto him, may be sure of right and interest to life eternal through him: But sinful and unworthy I (may the weak believer say) do believe the doctrine delivered by the Son of God, and do feel myself partly drawn powerfully to believe in him, by the sight of life in him, and partly driven, by the fear of God's wrath, to adhere unto him: Therefore I may be sure of my right and interest unto eternal life through him."

__________________
Richard
CofE
UK