Ask your Christian acquaintances and you will be surprised at the variety of answers elicited.
Many say, lack of prayer, and doubtless this is a tremendous lack, which words can scarcely exaggerate.
Others say, neglect of the Bible, and they have very much reason for so saying.
Others say, purpose of heart; or again, practical Christianity, or aggressiveness in the gospel, or a right understanding of the church.
But all these fail to give a true answer. I believe that to be THE KNOWLEDGE OF GOD. The necessary prayer of the Apostle Paul for the saints was that they might walk worthy of the Lord to all pleasing, being fruitful in every good work, and INCREASING BY THE KNOWLEDGE OF GOD.
The knowledge of God is the cause from which spring all happy and holy effects, such as prayerfulness, study of the Scriptures, aggressiveness in the gospel, the knowledge of the church, practical Christianity, etc.
If we know a person intimately we know what his interests and joys are, and we should not be intimate unless we shared those interests and joys, and the more intimate we are the more we shall understand and share in those interests and joys. And the finer character this person is the more it will prove the character of his associates. A thief consorts with a thief, a liar with a liar, but those who consort with God must be godlike.
Can a Christian know God and not be led out in fervent prayer for His interests, whether in the gospel field or among His own?
Can a Christian know God, and fail to study prayerfully and adoringly the book that reveals Him, and tells us of His varied interests?
Can a Christian know God and not be deeply interested in gospel work?
The good news is the gospel OF GOD. That it is of God is sufficient.
Can a Christian know God and not be interested in the church OF GOD of which he is a part, and which carries with it the heavenly calling and destiny?
Can a Christian know God and be uninterested in prophetic truth—the foretelling of God’s governmental ways in the earth?
Can a Christian know God and fail to be an example of practical Christianity?
The knowledge of God, then, is our great lack as Christians, not surely an absolute lack of that knowledge, for how could we be Christians if we did not know Him at all? But our knowledge is slender, scanty, superficial; communion is, alas! intermittent, feeble, poor.
But how are we to increase in this knowledge? Colossians 1:9-10 tells us that Paul prayed for it without ceasing for the saints. Surely then he prayed for it for himself. If the desire is awakened for it in our hearts, let us pray for it, let us cultivate intercourse with God in the reading of the Scriptures and in prayer and praise, bringing Him into all our circumstances, as, on the other hand, we seek to be interested in His interests and joys.
Above all God is made known in and through Christ, and it is in and through Christ we get to know God.
If Philip of old would ask of Jesus, “Show us the Father, and it suffices us,” the Lord could answer, “Have I been so long time with you, and yet hast thou not known ME, Philip? He that has seen ME has seen the Father” (John 14:8-9). “Be not conformed to this world, but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect will of God” (Rom. 12:2).