>Yes. The common theme seems to be love one another, this is universal.

There are actually quite a few similarities. For instance, the belief in some sort of afterlife (details vary in different beliefs).

>But when it come to person's salvation I think there is significant difference.

The basic message is the same, IMO.

>For instance, Christian faith, you can't earn you way into salvation nor can you work yourself into salvation. Salvation is only by grace of God, a free gift through J. Christ. It's up to you to accept or reject the gift.

That is the belief of some Christians. I don't think all Christians would agree with this.

I think there are actually quite a few places where we are told how we should behave, how to be a "good person". I don't think Christians are saved by only believing in Christ. They have a double responsibility: believe in Him, and obey Him.

The first paragraph of the "Most Holy Book" (by Bahá'u'lláh) states:

The first duty prescribed by God for His servants is
the recognition of Him Who is the Dayspring of
His Revelation and the Fountain of His laws, Who
representeth the Godhead in both the Kingdom of His
Cause and the world of creation. Whoso achieveth this
duty hath attained unto all good; and whoso is deprived
thereof hath gone astray, though he be the author of
every righteous deed. It behoveth every one who
reacheth this most sublime station, this summit of
transcendent glory, to observe every ordinance of Him
Who is the Desire of the world. These twin duties are
inseparable. Neither is acceptable without the other.
Thus hath it been decreed by Him Who is the Source of
Divine inspiration.

>In other religions, salvation is earned by being a "good" person by doing "good" deeds.

I don't believe that "only" believing in Christ, and completely disregarding all His teachings, will assure salvation for a person.