In using the sign of the cross before asking prayers to God, can you cite a verse in the bible ?

The Catholic Sign of the Cross is absolutely ancient, rooted not only in the Old Testament but the New (Apocalypse speaks of those who have the sign of God in their foreheads -- and those who have the sign of the Beast in their foreheads).

When Catholics undergo the Sacrament of Confirmation, the Bishop (sometimes a priest) seals the sign on our foreheads with holy chrism. St. John of Damascus wrote

This was given to us as a sign on our forehead, just as the circumcision was given to Israel: for by it we believers are separated and distinguished from unbelievers.

Crossing one's self recalls this seal, and the invocation that is said while making this holy sign calls on our God -- the Father, His Son, and the Holy Ghost -- and is a sign of our of belief; it is both a "mini-creed" that asserts our belief in the Triune God, and a prayer that invokes Him. The use of holy water when making this sign, such as we do when we enter a church, also recalls our Baptism and should bring to mind that we are born again of water and Spirit, thanks be to God.

Because of what the Sign indicates -- the very Cross of our salvation -- Satan hates it, and our using it makes demons flee. Make the Sign in times of temptation and confusion for great spiritual benefit!

Make the Sign of the Cross and make it often! Teach it to your children -- even the tiniest of children. If they're infants, take their hands and make the movements for them! Making the Sign should feel as natural as breathing...

I do not think it is Biblical. "Pray without ceasing" has no caveat with it that requires that gesture. I am not Catholic, but any technique that makes you get closer to God is a good thing, as I see it.

No. It is not overtly biblical.

Do you eat waffles? They aren't biblical either. Do you drive a car? Not biblical. Have you ever whistled "Dixie"? Unbiblical. Do you use a fork and knife when you eat meatloaf? Non-biblicalness galore.

Lots of very good things that Christians do are not biblical.

Of course!

http://www.newadvent.org/cathen/06423a.htm

In Christ

Fr. Joseph

No. It is an apostasy. The Catholic church's Bible is purposely changed so that the Ten Commandments conveniently fit their doctrines.

Check it out and compare!

GOD bless

Certain things, like praising God, asking his blessing, and routinely dedicating one's self to him, are so integral and essential to the authentic Christian faith that no particular scriptural basis is necessary ... or required.

But if you must, here goes:

Mat 18:1 At that hour the disciples came to Jesus, saying: Who, thinkest thou, is the greater in the kingdom of heaven?

Mat 18:2 And Jesus, calling unto him a little child, set him in the midst of them.

Mat 18:3 And said: amen I say to you, unless you be converted, and become as little children, you shall not enter into the kingdom of heaven.

Mat 18:4 Whosoever therefore shall humble himself as this little child, he is the greater in the kingdom of heaven.

Mat 23:37 Jerusalem, Jerusalem, thou that killest the prophets and stonest them that are sent unto thee, how often would I have gathered together thy children, as the hen doth gather her chickens under her wings, and thou wouldst not?

Of course one can. Did you mean to inquire as to whether or not one may?