1 Peter 1:3-9 (KJV)

3 Blessed be the God and Father of our Lord Jesus Christ, which according to his abundant mercy hath begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead,

4 To an inheritance incorruptible, and undefiled, and that fadeth not away, reserved in heaven for you,

5 Who are kept by the power of God through faith unto salvation ready to be revealed in the last time.

6 Wherein ye greatly rejoice, though now for a season, if need be, ye are in heaviness through manifold temptations:

7 That the trial of your faith, being much more precious than of gold that perisheth, though it be tried with fire, might be found unto praise and honour and glory at the appearing of Jesus Christ:

8 Whom having not seen, ye love; in whom, though now ye see him not, yet believing, ye rejoice with joy unspeakable and full of glory:

9 Receiving the end of your faith, even the salvation of your souls.

We have not seen seen Jesus Christ, we have not seen what He did on the cross yet we can and have believed the gospel. 
We believe that GOD has begotten us to a living hope. It was not because we wanted that but because He revealed Himself to us.

Matthew 16:16-17 (KJV)

16 And Simon Peter answered and said, Thou art the Christ, the Son of the living God.

17 And Jesus answered and said unto him, Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven.

That living hope was given to us because Jesus Christ has risen from the dead and Gods abundant mercy.
That resurrection assures us with an everlasting in-destructive inheritance that is waiting for us in heaven. Now, this is not because of us but because He wanted it and the LORD by His Own power is keeping/protecting/shielding us so we are preserved when we meet Him in heaven. Then our salvation will be complete as we will receive a new body that is incorruptible (1 Corinthians 15:53-54). The final victory over deaths. 
Therefore we can be full of joy despite of what we are going through and experiencing here on earth. These trials are there to prove and demonstrate the faith the LORD has given to us that it is unshakeable and even strengthen it more. This faith (believing in what we have not seen) is so precious that it can’t be compared to earthy riches like gold. When Jesus Christ is revealed this faith will bring praise, honour and glory to Him.
This precious faith in the gospel results in the salvation of our souls.
Let us comprehend more and more this great work of salvation that Jesus Christ has brought about on the cross for everyone who believes. John 20:29 (KJV) Jesus saith unto him, Thomas, because thou hast seen me, thou hast believed: blessed are they that have not seen, and yet have believed.