The mode of conversion varies greatly according to the former course of life. It may be a sudden crisis in the moral and intellectual life. This is very frequently the case in the experience of heathen who turn from the worship of idols to faith in Jesus Christ. A sudden crisis is frequently witnessed in the case of persons who, having lived a life of flagrant sin, renounce their former life. Conversion to them means a complete revolution in their thoughts, feelings and outward manner of life. In other instances conversion appears to be the climax of prolonged conflict for supremacy of divergent motives; and, again, it may be the goal of a gradual growth, the consummation of a process of discerning ever more clearly and yielding ever more definitely and thus experiencing ever more vitally truths which have been implanted and nurtured by Christian training. This process results in the conscious acceptance of Jesus Christ as the personal Savior and in the consecration of life to His service.
Thus conversion may be an instantaneous act, or a process which is more or less prolonged. The latter is more frequently seen in the case of children and young people who have grown up in Christian families and have received the benefit of Christian training. No conversions of this kind are recorded in the New Testament. This may be explained by the fact that most of our New Testament writings are addressed to the first generation of Christians, to men and women who were raised in Jewish legalism or heathen idolatry, and who turned to Christ after they had passed the age of adolescence. The religious life of their children as distinguished in its mode and manifestations from that of the adults does not appear to have been a matter of discussion or a source of perplexity so as to call forth specific instruction. Conversion comprises the characteristics both of repentance and of faith. Repentance is conversion viewed from its starting-point, the turning from the former life; faith indicates the objective point of conversion, the turning to God. (from International Standard Bible Encylopaedia, Electronic Database Copyright © 1996 by Biblesoft)
Matt 13:18 "Hear then the parable of the sower. 19 "When anyone hears the word of the kingdom, and does not understand it, the evil [one] comes and snatches away what has been sown in his heart. This is the one on whom seed was sown beside the road. 20 "And the one on whom seed was sown on the rocky places, this is the man who hears the word, and immediately receives it with joy; 21 yet he has no [firm] root in himself, but is [only] temporary, and when affliction or persecution arises because of the word, immediately he falls away. 22 "And the one on whom seed was sown among the thorns, this is the man who hears the word, and the worry of the world, and the deceitfulness of riches choke the word, and it becomes unfruitful. 23 "And the one on whom seed was sown on the good soil, this is the man who hears the word and understands it; who indeed bears fruit, and brings forth, some a hundredfold, some sixty, and some thirty."
Acts 8:9 "Now there was a certain man named Simon, who formerly was practicing magic in the city, and astonishing the people of Samaria, claiming to be someone great; 10 and they all, from smallest to greatest, were giving attention to him, saying, "This man is what is called the Great Power of God." 11 And they were giving him attention because he had for a long time astonished them with his magic arts. 12 But when they believed Philip preaching the good news about the kingdom of God and the name of Jesus Christ, they were being baptized, men and women alike. 13 And even Simon himself believed; and after being baptized, he continued on with Philip; and as he observed signs and great miracles taking place, he was constantly amazed. 14 Now when the apostles in Jerusalem heard that Samaria had received the word of God, they sent them Peter and John, 15 who came down and prayed for them, that they might receive the Holy Spirit. 16 For He had not yet fallen upon any of them; they had simply been baptized in the name of the Lord Jesus. 17 Then they [began] laying their hands on them, and they were receiving the Holy Spirit. 18 Now when Simon saw that the Spirit was bestowed through the laying on of the apostles' hands, he offered them money, 19 saying, "Give this authority to me as well, so that everyone on whom I lay my hands may receive the Holy Spirit." 20 But Peter said to him, "May your silver perish with you, because you thought you could obtain the gift of God with money! 21 "You have no part or portion in this matter, for your heart is not right before God. 22 "Therefore repent of this wickedness of yours, and pray the Lord that if possible, the intention of your heart may be forgiven you. 23 "For I see that you are in the gall of bitterness and in the bondage of iniquity." 24 But Simon answered and said, "Pray to the Lord for me yourselves, so that nothing of what you have said may come upon me."