1. There are several scriptures in which this doctrine is contained; as that in Rom. v. 14. where the apostle speaks concerning our fall in Adam, whom he calls, the _figure_[58] _of him that was to come_. Now, in what was Adam a type of Christ? Not as he was a man, consisting of soul and body; for, in that respect, all that lived before Christ, might as justly be called types of him. Whenever we read of any person, or things, being a type in scripture, there are some peculiar circumstances by which they may be distinguished from all other persons, or things that are not types. Now Adam was distinguished from all other persons, more especially as he was the federal head of all his posterity; and that he was so, appears from what the apostle not only occasionally mentions, but largely insists on, and shews in what respect this was true; and he particularly observes, that as one conveyed death the other was the head, or Prince of Life. These respective things indeed, were directly opposite, therefore the analogy, or resemblance, consisted only in the manner of conveying them; so that as death did not become due to us, in the first instance of our liableness to it, for our own actual sin, but the sin of Adam; that right we have to eternal life, by justification, is not the result of our own obedience, but Christ’s: This is plainly the apostle’s method of reasoning. Now, if Christ was, in this respect a federal Head and Representative of his people, then Adam, who is in this, or in nothing, his type, or figure, must be the Head of a covenant, in which his posterity were included. There is another scripture, by which this may be proved in 1 Cor. xv. 45-59. where the apostle speaks of the _first and second Adam_; by the latter he means Christ. Now, why should he be called the second man, who lived so many ages after Adam, if he did not design to speak of him, as typified by him, or bearing some resemblance of him? And, in other expressions, he seems to imply as much, and shews how we derive death from Adam, of whom he had been speaking, in the foregoing verses. Accordingly, he says, _The first man was of the earth, earthy: and, as is the earthy, such are they also that are earthy, and we have borne the image of the earthy_; so that if Adam was the root and occasion of all the miseries we endure in this world, arising from his violation of the covenant he was under, it plainly proves, that he was therein the head and representative of all his posterity.