Deuteronomy 13:6-9 “If your very own brother, or your son or daughter, or the wife you love, or your closest friend secretly entices you, saying: Let us go and worship other gods (gods that neither you nor your fathers have known, gods of the peoples around you, whether near or far, from one end of the land to the other, or gods of other religions), do not yield to him or listen to him. Show him no pity. Do not spare him or shield him. You must certainly put him to death. Your hand must be the first in putting him to death, and then the hands of all the people.”
Deuteronomy 17:3-5 “And he should go and worship other gods and bow down to them or to the sun or the moon or all the army of the heavens, …..and you must stone such one with stones and such one must die.“
2 Chronicles 15:13 “All who would not seek the LORD, the God of Israel, were to be put to death, whether small or great, man or woman.”
1 Then some Pharisees and teachers of the law came to Jesus from Jerusalem and asked,
2 “Why do your disciples break the tradition of the elders? They don’t wash their hands before they eat!”
3 Jesus replied, “And why do you break the command of God for the sake of your tradition?
4 For God said, ‘Honor your father and mother’ and ‘Anyone who curses his father or mother must be put to death.‘
5 But you say that if a man says to his father or mother, ‘Whatever help you might otherwise have received from me is a gift devoted to God,’
6 he is not to ‘honor his father’ with it. Thus you nullify the word of God for the sake of your tradition.
7 You hypocrites! Isaiah was right when he prophesied about you:
8 ” ‘These people honor me with their lips, but their hearts are far from me.
9 They worship me in vain; their teachings are but rules taught by men.'”
Romans 1:20-32 (from the New Testament) “20. For since the creation of the world God’s invisible qualities–his eternal power and divine nature–have been clearly seen, being understood from what has been made, so that men are without excuse.
21. For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened.
22. Although they claimed to be wise, they became fools
23. and exchanged the glory of the immortal God for images made to look like mortal man and birds and animals and reptiles.
24. Therefore God gave them over in the sinful desires of their hearts to sexual impurity for the degrading of their bodies with one another.
25. They exchanged the truth of God for a lie, and worshiped and served created things rather than the Creator–who is forever praised. Amen.
26. Because of this, God gave them over to shameful lusts. Even their women exchanged natural relations for unnatural ones.
27. In the same way the men also abandoned natural relations with women and were inflamed with lust for one another. Men committed indecent acts with other men, and received in themselves the due penalty for their perversion.
28. Furthermore, since they did not think it worthwhile to retain the knowledge of God, he gave them over to a depraved mind, to do what ought not to be done.
29. They have become filled with every kind of wickedness, evil, greed and depravity. They are full of envy, murder, strife, deceit and malice. They are gossips,
30. slanderers, God-haters, insolent, arrogant and boastful; they invent ways of doing evil; they disobey their parents;
31. they are senseless, faithless, heartless, ruthless.
32. Although they know God’s righteous decree that those who do such things deserve death, they not only continue to do these very things but also approve of those who practice them.”
Taken from: http://www.answering-christianity.com/death.htm