The scriptures teaches that faithfulness pleases God and He rewards faithfulness with eternal life.
No. He rewards us, but not with eternal life. Eternal life is a GIFT. You're confusing our rewards with salvation.
There is a crown of life given to those who are faithful unto death...that's called the
martyr's crown for they offered their very lives for the faith.
Revelation 2:10
Fear none of those things which thou shalt suffer: behold, the devil shall cast some of you into prison, that ye may be tried; and ye shall have tribulation ten days: be thou faithful unto death, and I will give thee a crown of life.
There is a crown of righteousness for those who love His appearing.
2 Timothy 4:8
Henceforth there is laid up for me a
crown of righteousness, which the Lord, the righteous judge, shall give me at that day: and not to me only, but
unto all them also that love his appearing.
There is also a
crown of glory for those who feed the flock in ministry. There is the
incorruptible crown for those who faithfully run the race, who crucify every selfish desire in the flesh and point men to Jesus. There is the
crown of rejoicing called the soul-winners crown. All those rewards He brings with Him.
There are also rewards in this life for faithful service, but eternal life is not a reward for our service. It's a gift of God given to those who trust JESUS and HIS WORK on the cross. A gift is not EARNED, it's freely given to those who
believe in Jesus Christ.
Romans 6:23
For the wages of sin is death; but
the gift of God is eternal life through Jesus Christ our Lord.