May not true believers, by reason of their imperfections, and the many temptations and sins they are overtaken with, fall away from the state of grace ?
True believers, by reason of the unchangeable love of God,1 and his decree and covenant to give them perseverance,2 their inseparable union with Christ,3 his continual intercession for them,4 and the Spirit and seed of God abiding in them,5 can neither totally nor finally fall away from the state of grace,6 but are kept by the power of God through faith unto salvation.7
Scripture proofs
The Westminster Assembly's proof texts (KJV). The bracketed numbers in the answer above mark the clause each set of references supports; expand a row to read the verses.
1 Jer. 31:3
The LORD hath appeared of old unto me, saying, Yea, I have loved thee with an everlasting love: therefore with lovingkindness have I drawn thee.
2 2 Tim. 2:19–21; 2 Sam. 23:5
2 Tim. 2:19 Nevertheless the foundation of God standeth sure, having this seal, The Lord knoweth them that are his. And, Let every one that nameth the name of Christ depart from iniquity.
2 Tim. 2:20 But in a great house there are not only vessels of gold and of silver, but also of wood and of earth; and some to honour, and some to dishonour.
2 Tim. 2:21 If a man therefore purge himself from these, he shall be a vessel unto honour, sanctified, and meet for the master’s use, and prepared unto every good work.
Although my house be not so with God; yet he hath made with me an everlasting covenant, ordered in all things, and sure: for this is all my salvation, and all my desire, although he make it not to grow.
3 1 Cor. 1:8–9
1 Cor. 1:8 Who shall also confirm you unto the end, that ye may be blameless in the day of our Lord Jesus Christ.
1 Cor. 1:9 God is faithful, by whom ye were called unto the fellowship of his Son Jesus Christ our Lord.
4 Heb. 7:25; Luke 22:32
Wherefore he is able also to save them to the uttermost that come unto God by him, seeing he ever liveth to make intercession for them.
But I have prayed for thee, that thy faith fail not: and when thou art converted, strengthen thy brethren.
5 1 John 2:27; 1 John 3:9
But the anointing which ye have received of him abideth in you, and ye need not that any man teach you: but as the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you, ye shall abide in him.
Whosoever is born of God doth not commit sin; for his seed remaineth in him: and he cannot sin, because he is born of God.
6 Jer. 32:40; John 10:28
And I will make an everlasting covenant with them, that I will not turn away from them, to do them good; but I will put my fear in their hearts, that they shall not depart from me.
And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand.
7 1 Pet. 1:5
Who are kept by the power of God through faith unto salvation ready to be revealed in the last time.
This doctrine across the Standards
Where the Confession and the Westminster Shorter Catechism treat the same matter, so the question can be studied alongside its parallel statements.
In the Westminster Confession
XVII.1 They whom God hath accepted in his Beloved, effectually called and sanctified by his Spirit, can neither totally …
They whom God hath accepted in his Beloved, effectually called and sanctified by his Spirit, can neither totally nor finally fall away from the state of grace; but shall certainly persevere therein to the end, and be eternally saved.
→ XVII.1 · Of the Perseverance of the SaintsXVII.2 This perseverance of the saints depends, not upon their own free will, but upon the immutability of the …
This perseverance of the saints depends, not upon their own free will, but upon the immutability of the decree of election, flowing from the free and unchangeable love of God the Father; upon the efficacy of the merit and intercession of Jesus Christ; the abiding of the Spirit and of the seed of God within them; and the nature of the covenant of grace: from all which ariseth also the certainty and infallibility thereof.
→ XVII.2 · Of the Perseverance of the SaintsXVII.3 Nevertheless they may, through the temptations of Satan and of the world, the prevalency of corruption remaining in …
Nevertheless they may, through the temptations of Satan and of the world, the prevalency of corruption remaining in them, and the neglect of the means of their preservation, fall into grievous sins; and for a time continue therein: whereby they incur God's displeasure, and grieve his Holy Spirit; come to be deprived of some measure of their graces and comforts; have their hearts hardened, and their consciences wounded; hurt and scandalize others, and bring temporal judgments upon themselves.
→ XVII.3 · Of the Perseverance of the SaintsIn the Westminster Shorter Catechism
Q.36 What are the benefits which in this life do accompany or flow from justification, adoption, and sanctification?
The benefits which in this life do accompany or flow from justification, adoption, and sanctification, are, assurance of God's love, peace of conscience, joy in the Holy Ghost, increase of grace, and perseverance therein to the end.
→ Open Q.36