Paul's conviction is very plain from numerous references in those wonderful heart-searching and heart-revealing letters of his. But one instance in this Book of Acts will serve as a fair illustration of his teaching and habit. It is in the nineteenth chapter. In his travels he has come as far as to Ephesus, and finds there a small company of earnest disciples. They are strangers to him. He longs to help them, but must first find their need. At once he puts a question to them. A question may be a great revealer. This one reveals his own conception of what must be the pivotal experience of every true follower of Jesus. He asks: "Did ye receive the Holy Spirit when ye believed?" But they had been poorly instructed, like many others since, and were not clear just what he meant. They had received the baptism of John--a baptism of repentance; but not the baptism of Jesus--a baptism of power. And Paul at once gives himself up to instructing and then praying with them until the promised gift is graciously bestowed. That is the last we hear of those twelve persons. Some of them may have been women. Some may have come to be leaders in that great Ephesian Church. But of that nothing is said. The emphasis remains on the fact that in Paul's mind because they were followers of the Lord Jesus they must have this empowering experience of the Holy Spirit's infilling. Plainly in this Book of Acts the pivot on which all else rests and turns is the unhindered presence of the Holy Spirit. Five Essentials. If you will stop a while to think into it you will find that a rightly rounded christian life has five essential characteristics. I mean essential in the same sense as that light is an essential to the eye. The eye's seeing depends wholly on light. If it does not see light, by and by, it cannot see light. The ear that hears no sound loses the power to hear sound. Light is essential to the healthful eye: sound to the ear: air to the lungs: blood to the heart. Just as really are these five things essential to a strong healthful christian life.