God has promised an end to tears, death, sorrow, crying, and pain. It's in the Bible, Revelation 21:4, TLB. "He will wipe away all tears from their eyes, and there shall be no more death, nor sorrow, nor crying, nor pain. All of that has gone forever."
Heaven will be a place of joy forever. It's in the Bible, Isaiah 35:10, TLB. "These, the ransomed of the Lord, will go home along that road to Zion, singing the songs of everlasting joy. For them all sorrow and all sighing will be gone forever; only joy and gladness will be there."
Grief does not last forever. It's in the Bible, Psalm 30:5, TLB. "Weeping may go on all night, but in the morning there is joy."
God will heal your grief. It's in the Bible, Psalm 147:3, TLB. "He heals the brokenhearted, binding up their wounds."
Jesus promised a Comforter. It's in the Bible, John 14:16, TLB. "If you love Me, obey Me; and I will ask the Father and He will give you another Comforter [the Holy Spirit], and He will never leave you."
Accept the promise of peace. It's in the Bible, John 14:27, TLB. "I am leaving you with a gift—peace of mind and heart! And the peace I give isn't fragile like the peace the world gives. So don't be troubled or afraid."
Hope in the future resurrection provides comfort in grief. It's in the Bible, I Thessalonians 4:13-17, NIV. "Brothers, we do not want you to be ignorant about those who fall asleep, or to grieve like the rest of men, who have no hope. We believe that Jesus died and rose again and so we believe that God will bring with Jesus those who have fallen asleep in Him. According to the Lord's own word, we tell you that we who are still alive, who are left till the coming of the Lord, will certainly not precede those who have fallen asleep. For the Lord Himself will come down from heaven, with a loud command, with the voice of the archangel and with the trumpet call of God, and the dead in Christ will rise first. After that, we who are still alive and are left will be caught up with them in the clouds to meet the Lord in the air. And so we will be with the Lord forever. Therefore encourage each other with these words."
The dead will live again. It's in the Bible, John 5:28-29, TLB. "Don't be so surprised! Indeed the time is coming when all the dead in their graves shall hear the voice of God's Son, and shall rise again—those who have done good, to eternal life; and those who have continued in evil, to judgment."