How do we know Jesus as the messiah and saviour of the world

  Firstly, in the old testament many different prophets through out a period  of over one thousand years foretold of the coming of Jesus Christ. As pope Leo xiii explained in 1900ad. At the beginning of the world  God has promised him as the conquerer of serpent"  (Gen. 3:15)  Hence succedingly ages had eargerly looked for his coming. The prophet had longed and clearly declared that all hope was on him.
Secondly , Jesus fulfilled this prophecies. As st Justin the martyr pointed out in 150 Ad (over 1500 years ago).


" Why should we believe a crucified man that he is the first born of the unbegotten son,  and that he will pass the judgement on the whole human race,  if we had not found the testimonies published about him before he came and was made man,  and if we had not seen this predicament fulfilled "

Thirdly Jesus proved his divinity by his grace , miracles and Teachings. Fourthly, Jesus'  own prophecies are still coming true , today , in the church he established and through out the world . Jesus is the same yesterday, today and forever (Heb. 13:8).