According to your religion or morality: how to make humans more united, respecting each other?

Actually , it is the plan of GOD who create mankind and scattered them to settle down in all parts of the world, as we witnesses ,by having different tribes,races and colors , in order that they would be acquainted to each others and help each others in their worldly affairs. Further more GOD send HIS only religion for all mankind, then HE called those who believe and practice as according to HIS only religion, as being brothers and sisters, or brethren or Muslims, who submitted their wills to the Will of GOD. At the same time, GOD forbid mankind not to create false religions by denying the real GOD and set up false gods to worship or become atheists ,as a whole, then create enmity among mankind ,by falsely claim of having tribalism, racism, nationalism,color distinction, liberalism, etc. To conclude , in order to bring perfect peace and justice to the last generation ,by promoting the unison and honor each others, among mankind, then GOD call this group of people as being the best nation on earth, by becoming the middle nation, who perform all goodness and forbid from all evils . So, this is how , my religion and the best moral  ,being send down by GOD, for all mankind of the last generation to uphold , before the last hour comes.

Religious rituals and traditions are a product of Tribal Unity that benefited the members of that Tribe! Cooperation and communal solidarity was a survival mechanism. Pride, bigotry and hatred of other thibes was another result. .

Bigotry is fueled by religious beliefs!  "My God is better than your God"

"My skin color is better than your skin color"!

White supremacist are deluded and uneducated!

Bigots see differences in people.

Open minded recognize similarities.

Teach everyone love (Colossians 3:14; 1 John 4:8).

God created human beings with free will, the right to choose His way, someone else's way, or our own way. As long as that is true, there can never be unity among human beings, and unfortunately, disunity inevitably leads to disrespect among some people.

I am okay with us being less united. If we all think the same way then we are all wrong the same way. Competition and the individual are worth preserving.

As for respect. Well I personally respect people who don't act horrible to other people. So to get more respect get less theists.

Teach us to love one another as we love ourselves.

Obviously, it would be to follow Jesus Christ, and to give glory in all things to God. If people loved God with all of their hearts, strengths, minds, and souls the World would be perfect.

According to Jesus Christ, we are to do unto others as we would have them do unto us. That's NOT the same as the older (negative) adage, 'Don't do to others what you don't want them to do to you." Jesus' positive instruction enables us to take the initiative to show love to them, even to our enemies. He also said to pray for those persecuting us. One Christians do that, then the other biblical principle is easy - to view everyone as having been made in the image of God, and worthy of respect for that reason. That means no Christian should look down on anybody else, but to do as the Bible tells us here:

"Have the same love [as Christ], being one in spirit and purpose. Do nothing out of selfish ambition or vain conceit, but in humility consider others better than yourselves. Each of you should look not only to your own interests, but also to the interests of others. Your attitude should be the same as that of Christ Jesus who, being in very nature God, did not consider equality with God something to be grasped, but made himself nothing, taking the very nature of a servant, being made in human likeness, and being found in appearance as a man, he humbled himself and became obedient to death - even death on a cross." Philippians 2:1-11

And Christians are also told that we were baptized by one Spirit into one body – whether Jews or Greeks, slave or free – and we were all given the one Spirit to drink” 1 Corinthians 12:13. Where Christians live that truth out, the world sees them as salt and light. Read also Galatians 3:28.

Only LOVE, with forgiveness and understanding can do this.

Read Mt. chapters 5-6-7, sermon on the mount, for starters.

You don't. Human beings were given free will and you can't legislate morality.