Authentic spirituality avoids the twin extremes of legalism and license. License is using God's grace to disregard the Law. Legalism is striving in the effort of the flesh to achieve a human standard of righteousness. It is easy to be victimized by the Pharasaic attitude that equates spirituality with conformity to an artificial code of behavior. Confusing the standards of Christians with Christian standards, many believers think that following a set of "dos and don'ts" leads to personal holiness.
Legalism emphasizes an external set of rules and prohibitions rather than the inner life in the Spirit. Because of the influence of a number of Judiazers, the Galatians fell into this error when they were in danger of exchanging their freedom in Christ for the yoke of the law (Galatians 5:1-8). In his corrective epistle to the Galatians, Paul stressed the crucial truth that the same principle that saves a believer (grace through faith) also sanctifies a believer.
Christian growth is not achieved by outer rules or ritual, but by an inner relationship. Christ-likeness is developed "through the Spirit, by faith" (Galatians 5:5).
The biblical balance between the excesses of legalism and license is liberty. Instead of doing what we have to do or doing as we please, we have the true freedom in Christ to do as He pleases. Liberty in Christ stresses inner transformation as the key to outer manifestation. Growth in grace is accomplished by knowing and depending upon the person of God. Lack of divine blessing comes from unbelief, not from failure of devotion.
To preach devotion first and blessing second, is to reverse God’s order, and preach law, not grace. The Law made man’s blessing depend on devotion; Grace confers undeserved, unconditional blessing: our devotion may follow, but does not always do so, in proper measure (William Newell).
Taken from Ken Boa’s Handbook to Spiritual Growth