1Jn 5:25; Eph 1:18–20; 2 Tim 1:8–9; ²Tit 3:4–5; Eph 2:4–5, 7–9; Rom 9:11; ³2 Cor 5:20; cf. 2 Cor 6:1–2; Jn 6:44; 2 Thes 2:13–14; ⁴Acts 26:18; 1 Cor 2:10, 12; ⁵Ezk 11:19; 36:26–27; Jn 6:45; ⁶Eph 2:5; Phil 2:13; Deut 30:6.

We know by experience that not everyone who hears the preaching of the Gospel finds salvation in Christ no matter how persuasive the sermon may be.

This fact of experience is confirmed in the Scriptures, which teaches us that the call of the Gospel is of two sorts, namely,—an external call and an internal or effectual call.

The external call is referred to by the Lord in the words: "For many are called, but few are chosen" (Mt 22:14). This call, which is issued to all without distinction, is issued in the preaching of the Gospel and is effectively the command to repent and believe in the Lord Jesus Christ for salvation. Not all who hear the Gospel will obey this summon.

The internal or effectual call, on the other hand, is taught in passages such as Romans 8:30, where we all taught that all who are called effectually, will be justified. This effectual call is given only to the elect (see 2 Tim 1:9; cf. 2 Th 2:13-14); and it is given according to ‘[God’s] free and special love to His elect, and from nothing in them moving Him thereunto’ (cf. Tit 3:4-5; Eph 2:4-5, 7-9; Rom 9:11). That is to say, it is given out of God’s good pleasure, and not because He foresaw that they would repent and believe, as the Arminians claim.

Like the external call, it is usually issued when the Word is preached, but unlike the external call, it is not so much a command to sinners, as it is a direct "work of God’s almighty power and grace" in the hearts of elect sinners. For this reason, it is ‘irresistible’ (cf. ‘Irresistible Grace’ of TULIP).

And for the same reason, the effectual call is sometimes known as ‘regeneration’ or the ‘new-birth’, although our Confession and Catechism, has, I believe, more correctly, included regeneration as a part of the effectual call rather than being equivalent to it (since the effectual call is not only about a change of nature as is regeneration, but about a response to the Word of God).

By what means is the effectual call effected? Our catechism teaches us that it is effected ‘by [God’s] Word and Spirit.’ The Holy Spirit is always the efficient cause or power in the effectual call, for it is He who regenerates (cf. Jn 3:3, 5, 8). Except in extraordinary circumstances (such as in the case of elect infants dying in infancy), the Holy Spirit always employs the external Word as the instrument or means of calling (cf. 1 Thes 1:5). The Word and the Spirit always operate together so that the power of the preaching is not derived from the piety or eloquence of the preacher. Thus the apostle Paul testifies to the Corinthians: "And my speech and my preaching was not with enticing words of man’s wisdom, but in demonstration of the Spirit and of power" (1 Cor 2:4).

How is the effectual call effected in the heart of the elect? The Holy Spirit effects it by ‘savingly enlightening their minds, renewing and powerfully determining their wills.’ The Scripture speaks of this work of the Spirit using a number of metaphors. For example the prophet Ezekiel speaks about God replacing our hearts of stone with hearts of flesh (Ezek 11:19; 36:26); and the apostle Paul speaks of our being raised from spiritual death (Eph 2:1, 5); and the Lord Himself speaks about spiritual eyes and ears (e.g. Mt 13:16). These metaphors emphasise the fact that in our regeneration and effectual calling, God illumines our understanding and changes our inclinations so that we are not only made sensible to the danger that attends our soul, but see the loveliness of Christ, and the grace of God in Him. It is in this way that God is said to renew and powerfully determine our wills. That is, since our will is determined by our inclinations, God’s working in our hearts to make Christ irresistible to us, essentially renews and determines our wills so that we are made to choose Christ.

What then is the effect of the effectual call, but that elect sinners who are hitherto dead in sin and trespasses, are ‘made willing and able freely to answer His call, and to accept and embrace the grace offered and conveyed therein.’ No violence is done to the will. Robert Shaw explains this most beautifully:

When does the effectual calling occur? It occurs in "God’s accepted time." In the Parable of the Vineyard (Mt 20:1-16), some are called early—like John the Baptist, some at the third hour, some at the sixth, some at the ninth and the rest at the eleventh hour—like the penitent thief on the cross.

We may also add that there is also a difference in the manner in which the Lord calls. Some are sweetly and gently drawn to the Saviour over a period of time, so that they can scarcely say with confidence when the change in heart began (e.g. many children who were catechised from young). Others experienced dramatic conversion under powerful preaching (e.g. the Philippian Jailer). Still others underwent a time of terror and burden of guilt under the Law before they find relief in the Gospel (e.g. the apostle Paul).W