Of course the OT God is not the same as the NT God. Paul of Tarsus, though born a Jew, was steeped in Greek thought. His Jesus is not a Jewish Messiah - a Warrior King who will punish all those who persecuted Jews. Pauls' Jesus is a Mediterranean Vegetation Hero, dying and being reborn as the crops are.

The problem is that the Vegetation Hero does not serve a God, but a Goddess - Gaia, Demeter and so on. Paul, who may or may not have been queer, but was certainly a misogynist and a patriarchalist, dreamed up a God who had the kindly, merciful and loving nature of the Goddess while still being male. The Catholic Church, originating in the same places as the vegetation cults, saw through this, hence the excessive devotion to the figures of the Virgin Mary, the Magdalene and Mary the Mother who watched her sons' execution (Maiden, Nymph and Crone, the three faces of the Goddess). This, mind you, despite the fact that the Gospels (written by men), who tried to minimise Jesus' mother and all but erased his wife/lover. The people were not fooled and gave these female figures their full measure of reverence.

Protestantism, which erases these female deities almost completely, along with most of the pantheon of Saints (minor gods) comes from the North, where the climate and the gods were a harsh, dour crowd. The Protestant God resembles Odin - giving men hard choices and testing their virtue and mettle - while the Protestant Jesus is All-Seeing Heimdall, who as Rig the Walker wandered the world teaching men how to live as Odin wanted them to.

You're all still pagans, but you won't admit it!