The apostle had kept to the basics, and he had been fairly simple with them in the way in which he had expressed the doctrines of the faith. He taught them not only the gospel while he was with them, and he had taught them the doctrines too, but he had expressed them as simply as they could be expressed.
What then does Paul mean by solid food? It is not to do with the level of doctrine; it is more to do with how you feed yourself from those Scriptures which talk about Christ, about holiness, about how to behave as Christians, how to live our lives and serve the Lord. ‘This passage tells me the duty, but I am not performing it. It tells me so much more of Christ, and it shows me how indebted I am to him. We feed ourselves for health and strength, and this is what the apostle means: do you feed yourself on the word? You could you could read about predestination and election, and those doctrines are important and true. You can read about the doctrines of grace, but are you at the same time so reading the word that day by day it affects you, and increases your commitment, and your concern for holiness.
‘I have fed you with milk and not with meat, for hitherto ye were not able to bear it.’ The words ‘to bear it’ are in italics; they have been added for clarity. ‘Neither yet now are ye able.’ There is a hindrance: you cannot take it in; it isn't all that interesting to you; your minds are still abuzz with earthly things. We see that all around us among Bible believing Christians today. There is so much trust in the flesh, in human ingenuity and devices, in human skills, in what can be added to the gospel. You go into to services in so many churches all around the country, and simple but profound worship has been abandoned. Now there has got to be all kinds of things added to it to gee it up, to improve upon it, to make an impression upon people. What is added are worldly things and worldly music: so little trust in the gospel and the power of the Spirit that all sorts of things must be added. The more worldly we are, as Christians, the less perception we have spiritually. The less appreciation we have, the less we can see of the deep things of God. That is how it is; that is the principle which is here.