This is one of the topics that bother me! One of the most common questions I see is 'Why is the God of the OT a tyrant, while the God of the NT seems so benevolent?'. In the OT, it DID seem that God was angry every day. Vengeful, wrathful, merciless.
Yet, in the NT, we are told that God is Love (1John 4:8). And in 1Corinthians 13 we are given the definition and qualities of love: Love is patient, Love is kind, isn't jealous, doesn't brag, isn't arrogant, doesn't act becomingly, does not seek it's own, is not provoked, doesn't take into account of a wrong suffered, doesn't rejoice in unrighteousness, but rejoices with the truth, bears all things, believes all things, hopes all things, endures all things, and never fails. So....if God is Love and love equals the above...then where is the anger? The wrath? The absent mercy?
Why does it seem like there's a great big contradiction here?
I think That God in the Old Testament was dealing with Israel according to Mosaic Law
An eye for an eye and a tooth for a tooth..and along these lines it is not difficult to understand that the people saw this as something that was not easy to attain. Finally comes the time for Christ and in the New Testament we see a different side Joh 3:16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.
So living under the law God acted by the Law because the promised Messiah had not yet been sent, after sending Christ then God began to show more the chracteristics of Grace... Even so The concept of grace still exists in the OT.
Psa 136:1 O give thanks unto the LORD; for he is good: for his mercy endureth for ever.
Psa 136:2 O give thanks unto the God of gods: for his mercy endureth for ever.
Psa 136:3 O give thanks to the Lord of lords: for his mercy endureth for ever.
Psa 136:4 To him who alone doeth great wonders: for his mercy endureth for ever.
Psa 136:5 To him that by wisdom made the heavens: for his mercy endureth for ever.
Psa 136:6 To him that stretched out the earth above the waters: for his mercy endureth for ever.
Psa 136:7 To him that made great lights: for his mercy endureth for ever:
Psa 136:8 The sun to rule by day: for his mercy endureth for ever:
Psa 136:9 The moon and stars to rule by night: for his mercy endureth for ever.
Psa 136:10 To him that smote Egypt in their firstborn: for his mercy endureth for ever:
Psa 136:11 And brought out Israel from among them: for his mercy endureth for ever:
Psa 136:12 With a strong hand, and with a stretched out arm: for his mercy endureth for ever.
Psa 136:13 To him which divided the Red sea into parts: for his mercy endureth for ever:
Psa 136:14 And made Israel to pass through the midst of it: for his mercy endureth for ever:
Psa 136:15 But overthrew Pharaoh and his host in the Red sea: for his mercy endureth for ever.
Psa 136:16 To him which led his people through the wilderness: for his mercy endureth for ever.
Psa 136:17 To him which smote great kings: for his mercy endureth for ever:
Psa 136:18 And slew famous kings: for his mercy endureth for ever:
Psa 136:19 Sihon king of the Amorites: for his mercy endureth for ever:
Psa 136:20 And Og the king of Bashan: for his mercy endureth for ever:
Psa 136:21 And gave their land for an heritage: for his mercy endureth for ever:
Psa 136:22 Even an heritage unto Israel his servant: for his mercy endureth for ever.
Psa 136:23 Who remembered us in our low estate: for his mercy endureth for ever:
Psa 136:24 And hath redeemed us from our enemies: for his mercy endureth for ever.
Psa 136:25 Who giveth food to all flesh: for his mercy endureth for ever.
Psa 136:26 O give thanks unto the God of heaven: for his mercy endureth for ever.