All three Gospel's that record Jesus baptism record this happening:
(Mark's Account) He saw the heavens splitting apart and the Holy Spirit descending on Him like a dove.
(Matthew's Account) After his baptism, as Jesus came up out of the water, the heavens were opened and he saw the Spirit of God descending like a dove and settling on him.
(Luke's Account) As he was praying, the heavens opened, and the Holy Spirit, in bodily form, descended on him like a dove.
Mark records it most graphically with 'the heavens being split apart'. This reminds me of the Veil of the Temple being rent at Jesus' death on the Cross (Mark 15:37-38). So, we see an 'opening' at the beginning and ending of Jesus' earthly ministry.
First, The Father opens the heavens to speak to The Son when He fulfill's the requirements of The Plan (at His Baptism). We see The Holy Spirit descend upon Jesus at this time and The Holy Spirit remains on Jesus' throughout His Life and Ministry. There is zero separation between Father and Son.
Last, The Father responds similarly when Jesus' fulfil's the requirements of The Plan (at His Crucifixion). There had been zero separation between Father and Son and now there wouldn't need be any separation between Father God and man...all who would follow Jesus as Lord and Savior. Now, The Holy Spirit who had descended upon Jesus' would be with all who followed Jesus as Lord and Savior. The Holy Place and The Most Holy Place was divided by the veil. When the veil was torn, access To God was given by Jesus' purchase of man on The Cross. There would be no more separation between Holy God and forgiven man.
Heaven was opened to you by the life, death and resurrection of Jesus. What are you doing about it? Are you living a life 'In The Spirit'. Are you living a life that fulfils the requirements of God's Plan for you? Jesus has afforded you access to God so that you can live an abundant life in Him. Let's get busy living it!