when jesus told by himself that I am sent for the israel alone why christans preach him to others ?

Answer 1

Because at the end of the Gospel of Matthew, Jesus says this:

"Go, therefore, and preach to ALL THE NATIONS, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you."

Answer 2

You are taking a passage out of context. I think you are talking about the woman who asked Jesus to heal her daughter if I'm not mistaken.

"He answered, "I was sent only to the lost sheep of the house of Israel." But she came and knelt before him, saying, "Lord, help me." And he answered, "It is not right to take the children's bread and throw it to the dogs." She said, "Yes, Lord, yet even the dogs eat the crumbs that fall from their masters' table." Then Jesus answered her, "O woman, great is your faith! Be it done for you as you desire." And her daughter was healed instantly. Matthew 15:24-28

But after Jesus had come to the Jews He told his disciples these things.

"And Jesus came and said to them, "All authority in heaven and on earth has been given to me. Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age." Matthew 28:18-20

"So when they had come together, they asked him, "Lord, will you at this time restore the kingdom to Israel?" He said to them, "It is not for you to know times or seasons that the Father has fixed by his own authority. But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth." And when he had said these things, as they were looking on, he was lifted up, and a cloud took him out of their sight. Acts 1:6-9

Answer 3

He was sent to Israel first. When they rejected Him He went to the Gentiles. This was prophesied even to Abraham when God made a covenant with him and told him that in him (in his seed-Christ) ALL the nations of the world would be blessed.

Answer 4

I think you may have the wrong version of the bible because Jesus started his testimony in Galiee and he started to preach to Gentiles.....please get an NIV(new international version) and read the passage you are refuring to from its orginal text

Answer 5

because He was a HEBREW and was under the Law, but when they refused to listen he also went to the Gentiles. Under the Law of Mosses there were two kind of people Jew or Israelite. hope that helps