Isaiah 35:1-2
“Even the wilderness and desert will be glad in those days. The wasteland will rejoice and blossom with spring crocuses. Yes, there will be an abundance of flowers and singing and joy! The deserts will become as green as the mountains of Lebanon, as lovely as Mount Carmel or the plain of Sharon. There the Lord will display his glory, the splendor of our God.”
Luke 12:27-28
“Look at the lilies and how they grow. They don’t work or make their clothing, yet Solomon in all his glory was not dressed as beautifully as they are. And if God cares so wonderfully for flowers that are here today and thrown into the fire tomorrow, he will certainly care for you. Why do you have so little faith?”
Job 14:2
“Like a flower he comes forth and withers. He also flees like a shadow and does not remain.”
Song of Songs 2:12
“Flowers appear on the earth; the season of singing has come, the cooing of doves is heard in our land.”
I'll give some context to some of the quotations here because I think they can be a little confusing without them.
For the Song of Songs passage:
"【She】
Like an apple tree among the trees of the forest is my beloved among the young men. I delight to sit in his shade, and his fruit is sweet to my taste. Let him lead me to the banquet hall, and let his banner over me be love. Strengthen me with raisins, refresh me with apples, for I am faint with love. 6 His left arm is under my head, and his right arm embraces me. Daughters of Jerusalem, I charge you by the gazelles and by the does of the field: Do not arouse or awaken love until it so desires. 8 Listen! My beloved! Look! Here he comes, leaping across the mountains, bounding over the hills. My beloved is like a gazelle or a young stag. Look! There he stands behind our wall, gazing through the windows, peering through the lattice. My beloved spoke and said to me, "Arise, my darling, my beautiful one, come with me. See! The winter is past; the rains are over and gone. Flowers appear on the earth; the season of singing has come, the cooing of doves is heard in our land. The fig tree forms its early fruit; the blossoming vines spread their fragrance. Arise, come, my darling; my beautiful one, come with me.""
Song of Songs is a love song between a man and a woman. Some say it is also a metaphor of the relationship between God and Israel, or God and the Church. I'm on the fence to whether this is true or not, but if it is: The general opinion is that the man is God and the woman is the Church/Israel. If that is the case, it means this passage is what we should be saying to God, not what God is saying to us.
Another thing worth noting: if you hold the position that SoS is about God and the church, you have no place whatsoever to complain about any romantic imagery in modern worship songs.
On the Job passage, the context is:
"Mortals, born of woman, are of few days and full of trouble. They spring up like flowers and wither away; like fleeting shadows, they do not endure. Do you fix your eye on them? Will you bring them before you for judgment? Who can bring what is pure from the impure? No one! A person's days are determined; you have decreed the number of his months and have set limits he cannot exceed."
Job was talking about human beings here. Basically, he was saying: life is short.
Song of Solomon 2:13
“The fig tree has ripened its figs, and the vines in blossom have given forth their fragrance. Arise, my darling, my beautiful one, and come along!”