There absolutely ARE aliens! Some are good, and some are not good.
I don’t know if there are “general” aliens on other planets, but it is possible. God has had thousands of years to create anything He wants to create, and He seems to like to create things. If so, God Almighty has a relationship with them whether they are good or evil. At some point, they will be accountable to God Almighty.
GOD IS AN ALIEN; therefore, Jesus is half alien [although mixed with human by God], and the Holy Spirit is an alien from God. Many humans have invited the Holy Spirit to live within them [in spirit]. Many humans depend on and lean on Jesus to save them from sin for eternity and to be in God’s Kingdom under Jesus Christ as King of Kings. It will be a dictatorship under God Almighty’s Will, under Jesus Christ [his son], and with the help of the Holy Spirit. However, the dictatorship will not be like the ones humans create. It will be much better.
There are God’s Angels, who are also angels who are in spirit form but can take on the appearance of human form when sent on tasks by God Almighty. God’s Angels do many complex tasks in the Universe [COMOS]. God’s Angels have and do come to and fro Heaven and Earth, and all in between.
Unfortunately, there are also evil Fallen Angels, Satan [who is an Angel], and demons [dead humans mixed with Angels in the past] who exist in space and on Earth. These entities come and go from space to Earth of their own will [allowed by God for now]. They influence the Leaders of the World, often individuals, and groups of people. They have evil agendas. [These entities hate humans because God Almighty has a plan for humans in his Kingdom. They are actually against God.] These angels can take human form or any other form they choose. They manipulate, trick, and mislead whenever possible for their own agenda.
BOTTOM LINE: There ARE aliens in space and on Earth.
There is NOW and there ALWAYS HAS BEEN!
There is a Spirit Realm, other Dimensions, and whatever else God Almighty wants to create, have created, etc.
Whether we believe it or not, there are [spacial] aliens that exist.