And he [the Lord] said unto me, My grace is sufficient for thee: for my strength is made perfect in weakness. Most gladly therefore will I rather glory in my infirmities, that the power of Christ may rest upon me. 2 Corinthians 12:9
圣经说，“我借着你冲入敌军， 借着我的力量跳过墙垣。”（诗18:29） 一个人可以跳过一些障碍，靠自己的意愿和努力；但是有的墙太高，他们靠自己是过不去的。诗人知道这些墙，这些只能靠着神的帮助才能跳过的墙。神不是简单的把人带到墙的另一边，他只是在人跳起来的时候，加了一把劲。
Conversion is that voluntary change in the mind of a sinner in which he turns on the one hand from sin and on the other hand to Christ. Conversion is the human side of the tremendous transformation that takes place in the divinely wrought “new birth,” or “regeneration.” It is simply man’s turning from sin to Christ.The Scripture teaches that god turns men to Himself, but men are also exhorted to turn themselves to God. God is represented as the author of the new heart and the new spirit, yet men are commanded to make for themselves a new heart and a new spirit. It is the old paradox of grace and free will. No one can be converted except by the grace of God, for we are too weak to turn ourselves, unaided; and we turn only in response to some stimulus provided outside ourselves.
But no one can be converted except with the consent of his own free will, because God does not override human choice. We may not be free to choose, because sin weakens our power of moral choice; but we are free to refuse. We can refuse to be chosen.
Simon Peter could not become a disciple until Jesus called him and said, “Follow Me.” But others heard the same call and refused it or put it off. One said, “Lord, let me first go and burry my father.” Another one said, “Let me first say farewell to those at my home.” These men refused Christ’s call.This combination of divine calling and the human responsibility of accepting of refusing God’s grace runs throughout the Bible and characterizes all God’s dealings with men.The Bible confronts us with man’s moral independence within himself and his spiritual dependence upon God.In the picturesque words of Psalm 18:29 (RSV), David says, “By my God I can leap over a wall.” A man can jump over some barriers by his own will and effort, but some walls are so high that they need more than this.The psalmist knew such walls. Those could be leaped only with the help of God. God does not lift a man over. God helps a man when he takes the leap.