Ch X, WCF:
1. All those whom God hath predestinated unto life, and those only, He is pleased, in His appointed and accepted time, effectually to call, (Rom. 8:30,Rom. 11:7, Eph. 1:10-11) by His word and Spirit, (2 Thess. 2:13-14, 2 Cor. 3:3,6) out of that state of sin and death, in which they are by nature to grace and salvation, by Jesus Christ; (Rom. 8:2, Eph. 2:1-5, 2 Tim. 1:9-10) enlightening their minds spiritually and savingly to understand the things of God, (Acts 26:18, 1 Cor. 2:10,12, Eph. 1:17-18) taking away their heart of stone, and giving unto them an heart of flesh; (Ezek. 36:26) renewing their wills, and, by His almighty power, determining them to that which is good, (Ezek. 11:19, Phil. 2:13, Deut. 30:6, Ezek. 36:27) and effectually drawing them to Jesus Christ: (Eph. 1:19, John 6:44-45) yet so, as they come most freely, being made willing by His grace. (Cant. 1:4, Ps. 110:3, John 6:37, Rom. 6:16-18)
2. This effectual call is of God’s free and special grace alone, not from any thing at all foreseen in man, (2 Tim. 1:9, Tit. 3:4-5, Eph. 2:4-5, 8-9) who is altogether passive therein, until, being quickened and renewed by the Holy Spirit, (1 Cor. 2:14, Rom. 8:7, Eph. 2:5) he is thereby enabled to answer this call, and to embrace the grace offered and conveyed in it. (John 6:37, John 5:25)
3. Elect infants, dying in infancy, are regenerated, and saved by Christ, through the Spirit, (Luke 18:15-16, Acts 2:38-39, John 3:3, 5, 1 John 5:12, Rom. 8:9) who worketh when, and where, and how He pleaseth: (John 3:8) so also are all other elect persons who are uncapable of being outwardly called by the ministry of the Word. (1 John 5:12, Acts 4:12)
4. Others, not elected, although they may be called by the ministry of the Word, (Matt. 22:14) and may have some common operations of the Spirit, (Matt. 7:22, Matt. 13:20-21, Heb. 6:4-5) yet they never truly come unto Christ, and therefore cannot be saved: (John 6:64-66, John 8:24) much less can men, not professing the Christian religion, be saved in any other way whatsoever, be they never so diligent to frame their lives according to the light of nature, and the laws of that religion they do profess. (Acts 4:12, John 14:6, Eph. 2:12, John 4:22, John 17:3) And to assert and maintain that they may, is very pernicious, and to be detested. (2 John 9-11, 1 Cor. 16:22, Gal. 1:6-8)
See expositions of the above here:
http://www.reformed.org/documents/shaw/shaw_10.html
AMR