Was Jesus the only begotten son of God?

In the book of Psalms 2:7 we find "I will declare the decree: the LORD hath said unto me, Thou art my Son; this day have I begotten thee." David, in this verse, is saying that God had told him he was the son of God and God has begotten him. Clearly Jesus is not the only begotten son of God.
Of course, one could say that although Jesus was not the only begotten son of God, he had no human father in contrast to David who had a human father. That is true! Since Jesus had no human father it makes the relationship between him and God a closer one. The question is what about Adam? Adam had no human father nor a human mother, and according to the Bible he too was the son of God. The Bible says, "And Jesus himself began to be about thirty years of age, being (as was supposed) the son of Joseph, which was the son of Heli." (Luke3:23) The Bible goes on to mention the supposed genealogy of Jesus Christ. At the end of this genealogy the Bible comes to Adam, and it says, "Which was the son of Enos, which was the son of Seth, which was the son of Adam, which was the son of God." (Luke 3:38). So Adam is also the son of God. According to the assumption: "because Jesus had no human father then he is closer to God than David who had a human father," we can safely conclude that Adam is better than Jesus because he did not have a human father or mother.
The truth is Jesus and Adam do not differ in God’s sight. They were a mere creation of God. The Holy Quran says in clear terms, "Verily, similitude of Jesus with God is as the similitude of Adam; He created him out of dust then said He unto him BE, and he became." (Ch 3: Vr 59).