Collins lays down series of rules for his congregation, that they may not swerve or fail in the faith. The first rule is discussed here.
The second rule give my Collins is
Be very well rooted and established in the right that has been delivered to you.
When the roots do not go down deep, one can easily be swayed. “There are many Christians that, through their own itching ears and the heaping up of teachers to themselves, have never been root or established in the truth.”
One without depth, cannot distinguish. Without a true “sight” of Christ, one will follow after existing affections and ideas. Christianity entails an entire renewing of the mind (Rom. 12:1-2). Collins expresses it thus, “You must not only hear the things of God, but see them; the first will but blind you, or best leave you in great uncertainty; the last will settle you.” There must be renovation of one’s heart.
This will require effort — and an effort which begins by beseeching the Lord to be the teacher, “In order to have a heart established through grace, get the Lord himself by prayer to teach you every truth. What Jesus Christ teaches once is everlastingly taught; no word is abiding, but what the Lord Jesus himself teaches.”
Here we see the great duty and burden of the church. The duty of the gathered people is to create disciples: those who are rooted and grounded in the truth. The truth must shape thought, affections and action. It is the duty of leaders to lead others in the way of truth (Heb. 13:7) and then to give an account for such leadership (Heb. 13:17). The new Christian will easily wonder if left utterly alone. The church is given to bring about this depth of life.
Yes, every individual Christian has the duty to learn the things of God, to study, prayer, mediate, serve, et cetera. But God did not give his Word to be lived in isolation but in communion. This depth takes place among the gathered people of God.