亚伯拉罕在经历了肉体、天然的力量被割除，并经历神是那全丰全足的供应者之后，他生出了以撒，经历神是称无为有的神。然而当以撒长大后，有一天神要他将以撒─神所赐给他的独生儿子，献回给神。这是亚伯拉罕一生中对神经历的最高峰，他相信神能使死人复活，就信而顺从的献上以撒。以撒生平的记载，含示恩典的经历。恩典的意思就是神临到我们，给我们享受。对以撒而言，每一件事都是恩典。他在恩典里出生，在恩典里长大，成为恩典的承继者。他的一生也是安息与享受的一生。今天，享受也是我们的定命。
耶和华按着先前的话，眷顾撒拉，使她在年老时怀孕。到了神所说的日期，当亚伯拉罕一百岁，撒拉九十岁的时候，以撒就照着神的应许（创二一1），在约定的时候，就是生命的时候出生了（二一2，十七21，十八10，14）。以撒这名的意思是“喜笑”，撒拉说，“神使我喜笑，凡听见的必与我一同喜笑。”（二一6）就着亚伯拉罕和撒拉而言，以撒的出生是一件大事。以撒的出生不是凭着亚伯拉罕天然的力量，也不是照着亚伯拉罕的时候，乃是凭着神恩典的工作，并照着神所约定生命的时候。以撒出生后，就渐渐长大，到了断奶的日子，亚伯拉罕为儿子设摆丰盛的筵席（1-8）。
以撒的出生有什么属灵的意义？这可从保罗在加拉太四章寓意的解释中看到。神呼召我们有一个目标，与祂呼召亚伯拉罕的目标相同，就是生出后裔。我们蒙召不是要产生好行为，而是要生出基督。然而，我们不是生出基督的正确人物。因着是基督徒，我们往往立志要活出好的美德，在学校中有好见证。但不久之后，就发现我们天然的人太难达到了，我们太难生出基督。因此，我们必须受割礼─我们天然的生命、力量、和我们的己必须被了结。这了结为那全丰全足者开路，进到我们这人里面作全丰全足的恩典，好生出基督。在教会生活、家庭生活和学校生活中，我们不是凭自己的努力作好弟兄、好姊妹、好儿女、好学生；乃是需要把真以撒─基督，生出来。不仅如此，我们所生出的基督必须长大。基督不仅必须成形在我们里面，也必须成形在我们中间（加四19）。在我们的日常生活和教会生活中，我们都需要彰显成形的基督；然后我们就会有丰盛的筵席，来享受神的恩典。
每日一问：以撒的出生不是凭人的力量，而是凭什么？这说明什么？
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The Birth and Growth of Isaac – Gal. 4:19
Abraham, after experiencing the cutting off of the flesh and his natural strength, and after experiencing God as the all-sufficient Supplier, brought forth Isaac, experiencing God as the One who calls things not being as being. However, when Isaac grew up, God asked him to offer up Isaac—the only son He had given him—back to God. This was the highest peak of Abraham’s experience of God in his life; he believed that God could raise the dead, and thus he believed and obeyed to offer up Isaac. The record of Isaac’s life implies the experience of grace. Grace means that God comes to us to be our enjoyment. For Isaac, everything was grace. He was born in grace, grew up in grace and became the heir of grace. His life was a life of rest and enjoyment. Today, enjoyment is also our destiny.
Jehovah visited Sarah according to His word, and she became pregnant in her old age. At the time appointed by God, when Abraham was 100 years old and Sarah was 90, Isaac was born according to God’s promise (Gen. 21:1), at the set time, which was the time of life (Gen. 21:2, 17:21, 18:10, 14). The name Isaac means “laughter”, as Sarah said, “God has made laughter for me; everyone who hears will laugh with me” (Gen. 21:6). As far as Abraham and Sarah were concerned, the birth of Isaac was a great event. Isaac’s birth was not by Abraham’s natural strength, nor was it according to Abraham’s time; rather, it was by the work of God’s grace and according to the time of life appointed by God. After Isaac was born, he grew, and on the day he was weaned, Abraham held a great feast for his son (Gen. 21:1-8).
What is the spiritual significance of Isaac’s birth? This can be seen from Paul’s allegorical explanation in Galatians chapter 4. God’s calling of us has a goal, the same goal as His calling of Abraham: to bring forth a seed. We are not called to produce good works, but to bring forth Christ. However, we are not the right person to bring forth Christ. As Christians, we often resolve to live out good virtues and have a good testimony in school. But shortly after, we discover that our natural man is too difficult to attain this; it is too hard for us to bring forth Christ. Therefore, we must be circumcised—our natural life, strength and our self must be terminated. This termination opens the way for the All-sufficient One to come into us as all-sufficient grace to bring forth Christ. In church life, family life and school life, we are not trying by our own effort to be good brothers, sisters, children or students; rather, we need to bring forth the real Isaac—Christ. Furthermore, the Christ we bring forth must grow. Christ must not only be formed in us but also formed among us (Gal. 4:19). In our daily life and church life, we all need to manifest the formed Christ; then we will have a rich feast to enjoy God’s grace.
Daily Question: Isaac’s birth was not by human strength, but by what? What does this signify?