When I first became involved in teaching God’s Word, I tended to assume that one of the great needs of Christians is to be instructed in the ‘deeper truths’ of the gospel. It was not long before experience (of my own life) and observation (of others’ lives) taught me how mistaken I had been. I began to see that in fact the ‘deeper truths’ (if there are such things) are really the old basic truths of the gospel. Far from being luxuries, they are necessities for Christian living.
Sinclair Ferguson (“The Christian Life”).