Why does it matter whether or not Jesus was literally raised from the dead?

Eternal life man

 

did you mention nonchristian sources that speaks about His life and ministry?

 

If Christ is not raised from the dead, there is no such thing as salvation...

[12] Now if Christ is proclaimed as raised from the dead, how can some of you say that there is no resurrection of the dead? [13] But if there is no resurrection of the dead, then not even Christ has been raised. [14] And if Christ has not been raised, then our preaching is in vain and your faith is in vain. [15] We are even found to be misrepresenting God, because we testified about God that he raised Christ, whom he did not raise if it is true that the dead are not raised. [16] For if the dead are not raised, not even Christ has been raised. [17] And if Christ has not been raised, your faith is futile and you are still in your sins. [18] Then those also who have fallen asleep in Christ have perished. [19] If in Christ we have hope in this life only, we are of all people most to be pitied. (1 Corinthians 15:12–19 ESV)​

Paul says it rather plainly: "And if Christ has not been raised, your faith is futile and you are still in your sins."

Blessings,

The Archangel

 

Romans 4:24-25 KJVS
But for us also, to whom it shall be imputed, if we believe on him that raised up Jesus our Lord from the dead; [25] Who was delivered for our offences, and was raised again for our justification.

 

for if dead persons do not rise, neither hath Christ risen, and if Christ hath not risen, vain is your faith, ye are yet in your sins; 1 Cor 15:16,17
This also id stated relative to Christ rising from the dead: Romans 6:9 knowing that Christ, having been raised up out of the dead, doth no more die, death over him hath no more lordship; and Acts 13:34 'And that He did raise him up out of the dead, no more to return to corruption, he hath said thus -- I will give to you the faithful kindnesses of David;

How many others have been raised out of the dead in that manner?

 

Would you agree with eternal life in incorruptible flesh?

because of this was my heart cheered, and my tongue was glad, and yet -- my flesh also shall rest on hope, because Thou wilt not leave my soul to hades, nor wilt Thou give Thy Kind One to see corruption; Acts 2:26,27 YLT

 

Some more perspectives, from a little John Gill c&p;
@
His By Grace--"John Gill: A Body of Doctrinal & Practical Divinity"-Doctrinal Book 5, Chapter 6

The effects of Christ's resurrection from the dead, or the ends which were to be, and have been, or will be, answered by it.

5a. First, With respect to God, the chief end of all, was his glory; for "Christ was raised from the dead by", some read it, to "the glory of the Father", #Ro 6:4 that is, "to the glory of God the Father", as in #Php 2:11 to the glory of his perfections; as particularly, his "truth" and "faithfulness", in fulfilling types, promises, and prophecies concerning this matter; for what the apostles and ministers of the New Testament say of it, is no other than what Moses and the prophets did say should come to pass; namely, "that Christ should suffer, and that he should be the first that should rise from the dead", #Ac 26:22,23 and since God spoke of it by them, the veracity of God required it should be done, and that is glorified by it. Also the "power" of God; to raise one from the dead, is the work of almighty power; as is both the resurrection of Christ, and of the saints; "God hath both raised up the Lord, and will also raise up us by his own power": and the exceeding greatness of his power was exerted in a most glorious manner in the resurrection of Christ, #1Co 6:14 Eph 1:19,20. Moreover, the "justice" of God is glorified in it; when Christ had done his work as a Surety, it was but just and equitable that he should be discharged, be loosed from the cords of death, and be detained no longer a prisoner in the grave; and that he should be honourably and legally acquitted; as he was when a messenger was dispatched from heaven to roll away the stone of the sepulchre, and set him free; and being thus raised from the dead, he was justified in the Spirit; and hereby the justice of God was glorified, as also his wisdom, grace, and goodness; which appeared in forming the scheme of salvation, and in the kind designs of God to his people; all which would have been defeated, if Christ had not been raised from the dead.

5b. Secondly, With respect to Christ.

5b1. Hereby is given further proof of his proper Deity, and divine Sonship; by this it appears, that he is the Lord God Almighty, who could and did raise himself from the dead! this declares him to be the Son of God with power: shows that he is the Lord of all, both of the dead and of the living; that he has the keys of hell and death, and can and will unlock the graves of his people, and set them free, as he has himself, #Ro 1:4 14:9 Re 1:18.

5b2. By this it is a clear case, that Christ has done his work as the Surety of his people; that he has paid all their debts, finished transgression, made an end of sin, made reconciliation for iniquity, and brought in everlasting righteousness; that he has fulfilled the law, satisfied justice, and obtained eternal redemption, having given a sufficient price for it; and, in short, has done everything he agreed to do, to the full satisfaction of his divine Father; and therefore he is raised from the dead, received into glory, and set down at the right hand of God, having answered all his suretyship engagements.

5b3. This shows that he has got the victory over death and the grave; that he has not only destroyed him that had the power of death, the devil, but has abolished death itself, the last enemy, and has brought life and immortality to light; that he has done what he resolved to do; "O death, I will be thy plague! O grave, I will be thy destruction!" so that the believer, in a view of interest in a risen Saviour, who has conquered death and the grave, may triumph, and say, "O death, where is thy sting? O grave, where is thy victory?" #2Ti 1:10 Ho 13:14 1Co 15:55.

5b4. It was necessary that Christ should rise from the dead, in order to enter into the glory promised him, and he prayed for: the prophets not only spoke of the sufferings of Christ, but of the glory that should follow; which could not be enjoyed by him, unless after he had suffered death, he was raised again; wherefore God raised him from the dead, and gave him the promised glory, #1Pe 1:11,21.

5c. Thirdly, With respect to his people; the power of Christ's resurrection is great; the effects of it are many, #Php 3:10.

5c1. The blessings of the covenant of grace in general are enjoyed by the saints in virtue of it; for though reconciliation, and other blessings of grace, are by the death of Christ; yet the application and enjoyment of them are through his interceding life, in consequence of his resurrection from the dead; to which life the whole of salvation is ascribed, #Ro 5:10 Heb 7:25.

5c2. Justification, in particular, is observed as one special end and effect of Christ's resurrection; "he was delivered for our offences, and was raised again for our justification"; and the triumph of faith, in the view of that blessing of grace, is rather, and more principally founded on Christ's resurrection, than on his sufferings and death, #Ro 4:25 #Ro 8:33,34.

5c3. Regeneration is another effect of Christ's resurrection; as the elect of God were "quickened with him", and in him, as their head and representative, when he was quickened and raised from the dead; hence said to be "raised up together", #Eph 2:5,6 so they are quickened in regeneration, in consequence and virtue of his resurrection, to which it is ascribed, #1Pe 1:3.

5c4. The resurrection of the saints at the last day is the fruit and effect of Christ's resurrection, and which is ensured by it. Christ's glorious body is the exemplar, according to which the bodies of the saints will then be formed; and his resurrection is the earnest and pledge of theirs; he is "the firstfruits of them that slept", that is, of the dead: the firstfruits are the sample, and what ensure a following harvest; so the resurrection of Christ is the sample, and gives assurance of the resurrection of the saints in time to come: so that Christ's resurrection being certain, the resurrection of the saints is also, #1Co 15:20,23 1Th 4:14.

 

1 Corithians 15:17, ". . . And if Christ be not raised, your faith is vain; ye are yet in your sins. . . ." There would have been no payment for sin. Christianity would be just one more superstition.

We have definitive evidence.
The New Testament documents from the first century churches.
Those of us whom God has saved know Him. Romans 8:16.
And the definitive date of His crucifixion and so resurrection can be scientificly and mathematically calculated. Re: per Mark 14:12. And Exodus 12:18.
Calendar Converter

 

One thing stand out more than anything else, its not that the professor did not believe in the bodily resurrection of Jesus Christ many don't... Why is it such a big deal?... HE JUST CALLED GOD A LIAR!... Brother Glen

John 10: 17 Therefore doth my Father love me, because I lay down my life, that I might take it again.

18 No man taketh it from me, but I lay it down of myself. I have power to lay it down, and I have power to take it again. This commandment have I received of my Father.

 

I think the question, Why is the resurrection of Jesus so important, is a very good one.

Here are some of the answers provided in the posts:
1) Because Jesus said He would be raised.
2) If Christ was not raised from the dead, our preaching is in vain and we are still in our sins.
3) Our faith will be counted as righteousness if we believe in the One who raised Jesus from the grave.

Some other answers have been posted but the above captures the answer.

Scripture says, and was cited at least twice above, Christ was raised for our justification. How are we justified? By being placed into Christ's spiritual body where we undergo the washing of regeneration. But why are we placed by God into Christ. Because He credits our faith as righteousness. And what bolsters our faith in the promises of God. The real word demonstration of God fulfilling His promise to raise Jesus from the dead. Thus He was raised to facilitate our justification through credited faith in the truth.