Sirona,
Yahweh doesn't seem very "constant" to me. The mosaic law was totally abolished with Jesus, for a starter. All those so called perfect laws were gotten rid of. Thats called change. One minute Jehovah is vengeful and kills whole societies of people, the next minute he is "saving" mankind because he's so loving.
Matt 5:17 "Think not that I came to destroy the Law, or the prophets. I came not to destroy, but to fulfill."
James 1:17 "Every good gift and every perfect gift is from above, and cometh down from the Father of lights, with whom is no variableness, neither shadow of turning."
Jesus is the same: Hebrews 13:8 "Jesus Christ the same yesterday, today, and forever."
The "change" most people is see is the outward. The various laws no longer needed, like sacrificing an animal for a sin offering. However, the change was only due to the ultimate sacrifice being paid for sins had been completed through Jesus. God has always been loving and it is demonstrated in the old testament. Look at the book of Jonah. Jonah wanted Nineveh destoyed. God wanted to punish them for there evil ways. However, when they repented, God had compassion on them and didn't destroy them. Why? He wants people to come to Him.
Also, the bible states that there are other gods. It refers to Satan as a god and at one point even Paul is suspected to be "a god".
The Bible does use the term "gods". Does that mean the are actually other "gods", beings of power on the same footing as God? No. I would challenge you to list me the verse where that it written. The Bible is quite clear that there is only one true God. I will agree that sometimes men thought other men were "gods". (Acts 14:11, Acts 28:6) The term was also used in the old testament, as a referencing a man as a "god". (Exodus 7:1) Did this mean that Moses was an actual god? No, it more implys that Moses held access to God's power to impress Pharoah. To Pharoah, Moses would appear a "god", but we know that Moses had no power of his own.
I hope this answers some questions for you.
God Bless!