But without faith it is impossible to please Him, for he who comes to God must believe that He is, and that He is a rewarder of those who diligently seek Him.
(Heb 11:6 NKJV)
Faith is necessary to please God
It is impossible to please God without faith; it could not be done in the Old Testament and it cannot be done now. One must believe God exists and that He will reward those who diligently seek Him. Those who do not believe this, of course, would never truly serve Him anyway.
Note that God is a rewarder. He is not just a punisher. He motivates by punishment, but also by reward. Some folks think only of punishments, as they fear the consequences of disobedience. Others think only of rewards, and even deny the existence of punishment. God clearly states His intent to give both, according to the conduct of men.
But we receive the reward only if we diligently seek Him. This requires action. Faith is not just something you have in your heart but do nothing, and yet you are rewarded. Faith must lead us to act as God has instructed. then He rewards us. This is true in all the cases found in the eleventh chapter of Hebrews, and it is taught in numerous places elsewhere. The faith that saves is the faith that obeys.
For other passages on obedience, see Matthew 7:21-27; 22:36-39; John 14:15,21-24; Acts 10:34,35; Romans 2:6-10; 6:17,18; Hebrews 5:9; Galatians 5:6; 2 Thessalonians 1:8,9; James 2:14-26; 1 Peter 1:22,23; 1 John 5:3; 2:3-6.
-- David Pratte