In short
Heaven is life in the full presence of God, where there is no more death, sorrow, or pain. Christians believe it is not mainly a place of clouds and harps but of restored relationship with God Himself, made possible through Jesus.Heaven's joy is God: to see Him face to face, to be fully known and fully loved, in a renewed creation where everything sad comes untrue. It is offered as a gift, not a wage, received by trusting Jesus.
The door to it is a Person, and He is holding it open for you.
What Scripture says
“And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away.”
Revelation 21:4 (KJV)“In my Father’s house are many mansions: if it were not so, I would have told you. I go to prepare a place for you.”
John 14:2 (KJV)Where to go from here
Still wondering? Ask Simon, a companion who points to Jesus, or bring it to God in prayer.