At the end of the day the cause can not be in the person. We have already seen that our wills are held in bondage and captivity to sin by nature as a result of the fall. The cause must therefore be with God and with his grace expressed powerfully in calling us to himself.
We call this activity of God effectual calling because it is effective in drawing sinners to him in Christ every time it is given. It is distinct from the general or outward call of God in the gospel which may and should go out to all calling them to repent and turn to Christ for salvation.
A very clear passage on this is John 6:35-44. Jesus is proclaiming himself as the Savior through whom spiritual life comes. He proclaims that “whoever comes”, and “whoever believes” will receive the salvation and blessing of God through him. The offer of Salvation goes out to all, no one is to be excluded. But some are responding in unbelief and refusing to come and he says two very important things in response.
-First in vs. 37 he says in response to this unbelief that all the Father have given him will come to him, in other words they will repent and believe. All those given to him by the Father are those the Father chose to be saved through him before the foundations of the world, those the Father predestined for salvation (Eph. 1).
-Secondly he says in vs. 44 in response to this unbelief that no one can come to him unless the Father who sent him draws them. Our Lord affirms the inability of man and the absolute necessity of the Father’s enabling action.
In these verses then we have the offer of the gospel to all together with an affirmation that the gospel will come to those predestined for Salvation through Christ and those only with an effectual power that brings them surely and savingly to Christ in faith.
II. This effectual call is of God’s free and special grace alone, not from anything at all foreseen in man, who is altogether passive therein, until, being quickened and renewed by the Holy Spirit, he is thereby enabled to answer this call, and to embrace the grace offered and conveyed in it.
 ROM 8:30 Moreover whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified. 11:7 What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded. EPH 1:10 That in the dispensation of the fulness of times he might gather together in one all things in Christ, both which are in heaven, and which are on earth; even in him: 11 In whom also we have obtained an inheritance, being predestinated according to the purpose of him who worketh all things after the counsel of his own will. 2TH 2:13 But we are bound to give thanks alway to God for you, brethren beloved of the Lord, because God hath from the beginning chosen you to salvation through sanctification of the Spirit and belief of the truth: 14 Whereunto he called you by our gospel, to the obtaining of the glory of our Lord Jesus Christ. 2CO 3:3 Forasmuch as ye are manifestly declared to be the epistle of Christ ministered by us, written not with ink, but with the Spirit of the living God; not in tables of stone, but in fleshy tables of the heart. 6 Who also hath made us able ministers of the new testament; not of the letter, but of the spirit: for the letter killeth, but the spirit giveth life.
 ROM 8:2 For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death. EPH 2:1 And you hath he quickened, who were dead in trespasses and sins; 2 Wherein in time past ye walked according to the course of this world, according to the prince of the power of the air, the spirit that now worketh in the children of disobedience: 3 Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others. 4 But God, who is rich in mercy, for his great love wherewith he loved us, 5 Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved). 2TI 1:9 Who hath saved us, and called us with an holy calling, not according to our works, but according to his own purpose and grace, which was given us in Christ Jesus before the world began, 10 But is now made manifest by the appearing of our Saviour Jesus Christ, who hath abolished death, and hath brought life and immortality to light through the gospel.
 ACT 26:18 To open their eyes, and to turn them from darkness to light, and from the power of Satan unto God, that they may receive forgiveness of sins, and inheritance among them which are sanctified by faith that is in me. 1CO 2:10 But God hath revealed them unto us by his Spirit: for the Spirit searcheth all things, yea, the deep things of God. 12 Now we have received, not the spirit of the world, but the spirit which is of God; that we might know the things that are freely given to us of God. EPH 1:17 That the God of our Lord Jesus Christ, the Father of glory, may give unto you the spirit of wisdom and revelation in the knowledge of him: 18 The eyes of your understanding being enlightened; that ye may know what is the hope of his calling, and what the riches of the glory of his inheritance in the saints.
 EZE 11:19 And I will give them one heart, and I will put a new spirit within you; and I will take the stony heart out of their flesh, and will give them an heart of flesh. PHI 2:13 For it is God which worketh in you both to will and to do of his good pleasure. DEU 30:6 And the Lord thy God will circumcise thine heart, and the heart of thy seed, to love the Lord thy God with all thine heart, and with all thy soul, that thou mayest live. EZE 36:27 And I will put my spirit within you, and cause you to walk in my statutes, and ye shall keep my judgments, and do them.
 EPH 1:19 And what is the exceeding greatness of his power to usward who believe, according to the working of his mighty power. JOH 6:44 No man can come to me, except the Father which hath sent me draw him: and I will raise him up at the last day. 45 It is written in the prophets, And they shall be all taught of God. Every man therefore that hath heard, and hath learned of the Father, cometh unto me.
 SON 1:4 Draw me, we will run after thee. PSA 110:3 Thy people shall be willing in the day of thy power, in the beauties of holiness from the womb of the morning: thou hast the dew of thy youth. JOH 6:37 All that the Father giveth me shall come to me; and him that cometh to me I will in no wise cast out. ROM 6:16 Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness? 17 But God be thanked, that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you. 18 Being then made free from sin, ye became the servants of righteousness.
 2TI 1:9 Who hath saved us, and called us with an holy calling, not according to our works, but according to his own purpose and grace, which was given us in Christ Jesus before the world began. TIT 3:4 But after that the kindness and love of God our Saviour toward man appeared, 5 Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost. EPH 2:4 But God, who is rich in mercy, for his great love wherewith he loved us, 5 Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved). 8 For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: 9 Not of works, lest any man should boast. ROM 9:11 For the children being not yet born, neither having done any good or evil, that the purpose of God according to election might stand, not of works, but of him that calleth.
 1CO 2:14 But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned. ROM 8:7 Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be. EPH 2:5 Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved).
 JOH 6:37 All that the Father giveth me shall come to me; and him that cometh to me I will in no wise cast out. EZE 36:37 Thus saith the Lord God; I will yet for this be inquired of by the house of Israel, to do it for them; I will increase them with men like a flock. JOH 5:25 Verily, verily, I say unto you, The hour is coming, and now is, when the dead shall hear the voice of the Son of God: and they that hear shall live.