Murti-puja is a valid method of worship practiced for millennia among most hindus traditions or sampradayas.
Murti pujas provides a focus for worship and a reminder of god virtues as described in the shastras when a murti is consecrated in accordance with vedic and agamic rituals in mandirs that murtis is belieed to be the manifestation of the divine.
Thereafter, worship of the murtis is believed to tantamount to direct worship of the deity. The devotee can them express and develop his or her devotional attachment to god in various ways.
Because og God’s murtis the the devotee is inspired and develops feelings of love, faith, humality, instrospection, repentance, glory and indebtedness. He or she also experiences divinity and peace of mind by doing darshan of and meditatin upon the scared image. The devotee also prays and make resolutions for self improvement due to the physical presence of the sacred image.