An-Nisaa (The Women)

136. "O' you who have Faith believe in Allah and His Messenger and the Book which He has sent down unto His Messenger, and the Book (S) which He has sent down a foretime; and whoever disbelieves in Allah and His angels and His Messengers and the Last Day, has indeed gone astray into far error."

The meaning of the verse may be such: O' you who have faith! Go a step further; or, be firm in your faith forever.

A believer should elevate himself to a higher degree of faith every day, since there are degrees in faith.

"O' you who have Faith! Believe..."

In this regard, Surah Muhammad, No.47, verse 17 says:

"And those who avail of the guidance, He adds unto them guidance..."

And, Surah Al-Fath No.48 verse 4 says:

"... that they might add further faith to their faith…."

However, disbelief, in some heavenly Books and some prophets is the same as disbelief in all.

"... Believe in Allah and His Messenger and the Book which He has sent down unto His Messenger, and the Book(S) which He has sent down a foretime; and whoever, disbelieves in Allah and His angels and His Messengers and the Last Day, has indeed gone astray into far error. "