Willful sin means comitting sin knowingly, and with a desire to do sin.
If you mean by namaz praying or salat, then it is a big sin for not doing it. If you doing it intentionally and knowingly, then your are not considered Muslim.
rebellion
that sin and blasphemy are bad and and blasphemy is the only unforgivable sin
Corporate sin is when a group of people get together and jointly and knowingly commit a sin.
Nowhere in the Bible does it say that.
The Bible does not explicitly say that no sin is greater than another. However, it does teach that all sins separate us from God and that the consequences of sin are serious.
no
sin
Members of the Church of Jesus Christ of Latter-day Saints (the "Mormon" church) do not believe that being human is a sin. They believe that sinning is knowingly disobeying God.
The Bible says very clearly that rebellion is like witchcraft. It says that like witchcraft is a sin, so is rebellion a sin.
James 4:17 - Therefore, to him who knows to do good and does not do it, to him it is sin. [NKJV]