Let us find out which deities grace us with their presence in a marriage that has been performed in a ritual which includes all the mantras
First would be the 'Ganapati puja' hence we invite Lord Ganapathi (Lord Ganesh) to the wedding. He would recieve our prayers and invite the eternal groom ,Lord Sri MahaVishnu and his ever beautiful, blushing bride Devi Sri Lakshmi. Lord Ganapati would recieve them and after settleing them at the altar he leaves. Sri Mahavishnu is the oone who stays at the altar and presides over the wedding ceremony.
The news that lord Vishnu is coming is spread by Garuda ( the vehicle of Lord Vishnu) to all the deities. Hence all the deities arrive to the altar before him to invite him. The 'astadikpalakulu' - the rulers/guardians of the eight directions 'Lord Indra'(the ruler of East), 'Lord Varuna' (the ruler of west), 'Lord Kubera' (the ruler of North), 'Lord Yamudu' (the ruler of South), 'Lord Agni'(ruler of south-east), 'Lord Nirruti'(ruler of south-west), 'Lord Vayuvu'(ruler of north-west), 'Lord Esanuvu' (ruler of north-east).
Along with the above mentioned come the servants of the Lords, their sevants, devotees and the residents of Vikumtam and Kailasam also grace us with their presence. Along with them come, Vasista- Atri - Bharatvaja - Viswamitra- Gautama - Kasyapa- Jamadagni the 'Saptarishis' along with their wives to bless the marrying the couple. When the marriage ceremony done with such mantras that could include such a gathering of deities and include their blessings then it would be a loss not to perform the wedding in such a manner.