“The Holy Spirit will come upon you, and the power of the Most High will overshadow you; and for that reason the holy thing being begotten will be called the Son of God” (Luke 1:35).
The word translated as “overshadow” is episkiazo and means “to rest upon” or “cast a shadow”.
Each believer has an experience not unlike that of Mary; the holy Son becomes born in me by a direct act of God. It is the sudden act of finding oneself in the shadow of God that leads to faith.
But that is the beginning only. We are, at that point, still babes, accustomed only to milk, “unskilled in the word of righteousness” (Hebrews 5:13). We are dependent upon others for the provision of our food. That is natural enough for the newborn, but food is meant to make us grow so that ultimately we can be independent of men and dependent only upon God. Then He will feed us on solid food, for “solid food is for the mature, those who, through repeated practice and exercise, are having the capacity to discern trained for differentiating between good and evil” (Hebrews 5:14).
Milk, then, is an unsatisfactory diet for one who needs to grow to maturity; it is not good enough for those who are in need of strong meat.
Unfortunately, this is where modern Christianity is today; the faithful gather together to hear a message given by a hireling; he feeds them what they want to hear, but it is milk only. Strong meat can only come from God. This explains the chronic immaturity and dependence of the Christian Church today.
Being overshadowed so as faith can be conceived is one thing; going on to have Christ formed in me (Galatians 4:19) is something else. The process of sanctification is nothing less than Christ being formed in me. It takes a diet of the strong meat of the word to do that.