You live in a world where your soul is in constant danger. Enemies are round you on every side. Your own heart is deceitful. Bad examples are numerous. Satan is always laboring to lead you astray. Above all false doctrine and false teachers of every kind abound. This is your great danger.
To be safe you must be well armed. You must provide yourself with the weapons which God has given you for your help. You must store your mind with Holy Scripture. This is to be well armed.
Arm yourself with a thorough knowledge of the written word of God. Read your Bible regularly. Become familiar with your Bible. . . . Neglect your Bible and nothing that I know of can prevent you from error if a plausible advocate of false teaching shall happen to meet you. Make it a rule to believe nothing except it can be proved from Scripture. The Bible alone is infallible. . . . Do you really use your Bible as much as you ought?
There are many today, who believe the Bible, yet read it very little. Does your conscience tell you that you are one of these persons?
If so, you are the man that is likely to get little help from the Bible in time of need. Trial is a sifting experience. . . . Your store of Bible consolations may one day run very low.
If so, you are the man that is unlikely to become established in the truth. I shall not be surprised to hear that you are troubled with doubts and questions about assurance, grace, faith, perseverance, etc. The devil is an old and cunning enemy. He can quote Scripture readily enough when he pleases. Now you are not sufficiently ready with your weapons to fight a good fight with him. . . . Your sword is held loosely in your hand.
If so, you are the man that is likely to make mistakes in life. I shall not wonder if I am told that you have problems in your marriage, problems with your children, problems about the conduct of your family and about the company you keep. The world you steer through is full of rocks, shoals and sandbanks. You are not sufficiently familiar either with lighthouses or charts.
If so, you are the man who is likely to be carried away by some false teacher for a time. It will not surprise me if I hear that one of these clever eloquent men who can make a convincing presentation is leading you into error. You are in need of ballast (truth); no wonder if you are tossed to and fro like a cork on the waves.
All these are uncomfortable situations. I want you to escape them all. Take the advice I offer you today. Do not merely read your Bible a little—but read it a great deal. . . . Remember your many enemies. Be armed!
—J.C. Ryle
Quoted by J.I. Packer in 18 Words: The Most Important Words You Will Ever Know