Dear Confused,

Jesus speaks about Hell in His teachings and parables much more than it is mentioned in the
Old Testament; and the word mercy is mentioned much more in the Old Testament than it is in the New Testament.

God in the Old Testament tends to get a bum rap from people who do not take the Word of God in its proper context. We must remember that God in the Old Testament was dealing with a people in ancient times living in a pagan world, and His main "challenge" was to wean them away from a pagan polytheistic world with its skewed moral norms. To a people who have not been touched by the new dispensation of grace that Christ won for the world, the goodness of God may seem demanding and scary, similar to how a naughty child might see a just father and his love. This principle of seeing justice as harshness is present for pre-Christians as well as post-Christians. (modern secularists)

So I wouldn't say God and His love was different for mankind in the Old Testament than it was in the New Testament; but it may have been manifested differently because of where man was in his spiritual maturity. Perhaps the tough love we read in the Bible may seem to us as being harsh, when it was not experienced that way at all by the ancient Israelites.

Peace,

Paul