Russian for "go with God" is ступай с Богом. It is pronounced stupai s bogom.
Bog
This word means 'Oh god' in Russian,same as OMG and Oh my god.
Not sure what is meant by "the old Russian". An old Russian person would call God the same as a young Russian would. If the question is about the old Russian language (the Old Church Slavonic), the word for God is one of the few that have not changed in modern Russian.Regardless, the answer is bog.If addressing God in a plea, as in God save Russia, then it's bozhe.Finally, a Russian may refer to God as Lord, in which case it becomes gospot.
"God of Death" in Russian would be Bog Smerti.
"Without god" in Russian is без бога, pronounced bez boga
The Russian word for "so" is "так" (tak).
Dazhbogm (also Dadzbog), the Russian god of the sun, son of the sky god Svarog, and brother to fire god Svarozhich.
russian word for naughty
You can write "Бог благословит тебя" in Russian, which translates to "God bless you."
Замечательно is the Russian word for wonderful.
The the word number in Russian is номер.
мужество is the Russian Word for courage